Effects of vitamin D on serum lipid profile in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

Vitamin D and Dyslipidemia: Is There Really a Link? A Narrative Review

Nowadays, the interest in the extraskeletal effects of vitamin D is growing. In the literature, its several possible actions have been confirmed. Vitamin D seems to have a regulatory role in many different fields-inflammation, immunity, and the endocrine system-and many studies would demonstrate a possible correlation between vitamin D and cardiovascular disease. In this paper, we deepened the relationship between vitamin D and dyslipidemia by reviewing the available literature. The results are not entirely clear-cut: on the one hand, numerous observational studies suggest a link between higher serum vitamin D levels and a beneficial lipid profile, while on the other hand, interventional studies do not demonstrate a significant effect. Understanding the possible relationship between vitamin D and dyslipidemia may represent a turning point: another link between vitamin D and the cardiovascular system.

Effects of vitamin D supplementation on metabolic parameters, serum irisin and obesity values in women with subclinical hypothyroidism: a double-blind randomized controlled trial

Purpose

Subclinical hypothyroidism is an early, mild form of hypothyroidism that may progress to overt hypothyroidism if untreated. The current study aimed to assess the effects of vitamin D supplementation on hormonal (thyroid stimulating hormone [TSH], triiodothyronine, thyroxine, and free thyroxine) parameters, lipid profiles, serum irisin, and obesity indices in women with subclinical hypothyroidism.

Methods

The present randomized, double-blind, placebo-controlled clinical trial was carried out on 44 women with subclinical hypothyroidism. The participants were allocated to two groups (22 patients in each group) that received vitamin D (50,000 IU/week) or placebo for 12 weeks. Fasting blood samples, anthropometric and body composition measurements, physical activity levels, and dietary intakes were collected at baseline and at the end of the study.

Results

Vitamin D supplementation significantly decreased TSH, total cholesterol, and fat mass percentage, and significantly increased serum vitamin D and irisin levels and fat-free mass percentage compared to the control group (all, p<0.05). Changes in thyroid hormones, other lipid profiles, and anthropometric indices were not significantly different between the groups.

Conclusion

Our study indicates that vitamin D administration improves serum TSH, total cholesterol, irisin, and body composition in women with subclinical hypothyroidism. More well-designed clinical trials are required to confirm these findings and clarify the effects of vitamin D supplementation on both genders of patients.Clinical trial registration: https://www.irct.ir/trial/57482, Identifier IRCT20100408003664N25.

Are There Any Pleiotropic Benefits of Vitamin D in Patients With Diabetic Kidney Disease? A Systematic Review of Randomized Controlled Trials

Background

Type 2 diabetes (T2D) and kidney disease are risk factors for vitamin D deficiency. Native forms of vitamin D have a lower risk of hypercalcemia than calcitriol, the active hormone. The enzyme responsible for activating native vitamin D is now known to be expressed throughout the body; therefore, native vitamin D may have clinically relevant effects in many body systems.

Objective

The objective of this systematic review was to examine the effect of native vitamin D supplementation on clinical outcomes and surrogate laboratory measures in patients with T2D and diabetic kidney disease (DKD).

Design

Systematic review.

Setting

Randomized controlled trials (RCTs) conducted in any country.

Patients

Adults with T2D and DKD receiving supplementation with any form of native vitamin D (eg, ergocalciferol, cholecalciferol, calcifediol).

Measurements

Clinical outcomes and surrogate clinical and laboratory measures reported in each of the trials were included in this review.

Methods

The following databases were searched from inception to January 31, 2023: Embase, MEDLINE, Cochrane CENTRAL, Web of Science, ProQuest Dissertations and Theses, and medRxiv. Only RCTs examining supplementation with a native vitamin D form with a control or placebo comparison group were included. We excluded studies reporting only vitamin D status or mineral metabolism parameters, without any other outcomes of clinical relevance or surrogate laboratory measures. Study quality was evaluated using the Cochrane risk-of-bias tool (RoB2). Results were synthesized in summary tables for each type of outcome with the P values from the original studies displayed.

Results

Nine publications were included, corresponding to 5 separate RCTs (377 participants total). Mean age ranged from 40 to 63. All trials administered vitamin D3. Intervention groups experienced improvements in vitamin D status and a reduction in proteinuria in 4 of the 5 included RCTs. There was a decrease in low-density lipoprotein and total cholesterol in the 2 trials in which they were measured. Improvements in bone mass, flow-mediated dilation, and inflammation were also reported, but each was only measured in 1 RCT. Effects on glucose metabolism, high-density lipoprotein, triglycerides, blood pressure, oxidative stress, and kidney function were mixed. No serious adverse effects were reported.

Limitations

Limitations include the small number of RCTs and lack of information on the use of drugs that affect measured outcomes (eg, proteinuria-lowering renin-angiotensin-aldosterone system inhibitors and lipid-lowering medication) in most studies. Our study is also limited by the absence of a prestudy protocol and registration.

Conclusions

Native vitamin D is a safe treatment that improves vitamin D status in patients with DKD. Vitamin D may modify proteinuria and lipid metabolism in DKD, but further well-designed trials that include well-established treatments are necessary. Overall, there is limited evidence for beneficial pleiotropic effects of vitamin D in patients with DKD.

Effect of oral versus parenteral vitamin D3 supplementation on nuclear factor-κB and platelet aggregation in type 2 diabetic patients

Platelet hyperactivity is one of the key factors implicated in the development and progression of diabetic vascular complications. Activated platelets mediate leukocyte recruitment that further enhances inflammatory responses in vascular wall ultimately resulting in atherosclerotic complications. Since vitamin D insufficiency is highly prevalent in diabetics, we aimed to evaluate the effect of three dosage forms of vitamin D supplementation on lipid profile, NF-κB, platelet aggregation, and platelet calcium content in type 2 diabetic patients. Type 2 diabetic patients were randomized to receive daily (4000 IU/day) or weekly (50 000 IU/week) oral vitamin D3 for 3 months. Another group received a single parenteral dose (300 000 IU) of vitamin D3, whereas the control group received their antidiabetic drug(s) alone. Serum 25(OH)D, total cholesterol, triglycerides, high- and low-density lipoprotein cholesterol, NF-κB, and platelet aggregation were measured at the beginning and 3 months after vitamin D supplementation. Platelet calcium content was evaluated by measuring the fluorescence intensity of Rhod-2-stained platelets by confocal fluorescence microscopy. Results showed that serum 25(OH)D3 levels significantly increased in all vitamin D3-treated groups. However, the mean level for parenteral treated group was significantly lower than oral-treated groups. Oral and parenteral treatment were also able to decrease NF-κB level, platelet aggregation, and platelet calcium content. However, both oral doses of vitamin D3 were superior to the single parenteral dose. In conclusion, restoring normal levels of vitamin D is an important determinant to maintain normal platelet function and reduce inflammation. Nevertheless, further long-term studies are still needed.

The Effect of Vitamin D Supplementation on Lipid Profiles: an Umbrella Review of Meta-Analyses

According to published meta-analyses, vitamin D exerts different beneficial effects in preventing and controlling risk factors associated with noncommunicable chronic diseases; however, the results are still conflicting. The purpose of this umbrella meta-analysis was to investigate the effect of vitamin D supplementation on low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol (TC), and triglyceride (TG) as components of the lipid profile. PubMed, Scopus, Web of Science, and Cochrane Database of Systematic Reviews were systematically searched for meta-analyses of randomized controlled trials. The umbrella meta-analysis followed the PRISMA guidelines. The random-effects model was employed to estimate the overall effect size (ES). Overall, 25 meta-analyses were included. In the standardized mean difference analysis, vitamin D significantly decreased TG (ES: -0.15; 95% CI: -0.23, -0.08; P ≤ 0.001) and TC levels (ES: -0.17; 95% CI: -0.23, -0.11; P ≤ 0.001) and increased HDL levels (ES: 0.08; 95% CI: 0.01, 0.15; P = 0.025). In the weighted mean difference analysis, vitamin D significantly decreased only TG levels (ES: -4.63 mg/dL; 95% CI: -7.70, -1.57; P = 0.003). The present study supports that vitamin D supplementation could be considered a beneficial adjuvant therapy in managing lipid profile levels, especially in individuals with vitamin D deficiency. This systematic review was registered in PROSPERO as CRD42022306334.

Modulatory Properties of Vitamin D in Type 2 Diabetic Patients: A Focus on Inflammation and Dyslipidemia

BACKGROUND

Evidence from preclinical studies has found a correlation between the development of type 2 diabetes (T2D) and vitamin D deficiency. However, evidence from randomized controlled trials (RCTs) revealed inconclusive results on vitamin D supplementation. We explored the effect of vitamin D on inflammation and dyslipidemia in T2D.

METHODS

We comprehensively searched for RCTs evaluating the effect of vitamin D in T2D on PubMed. Data were analyzed using Review Manager 5.3 and reports, such as standardized mean difference (SMD) and 95% confidence intervals (CI) at a 5% significant level using a random effect model.

RESULTS

This study revealed a significant reduction in tumor necrosis factor-alpha (TNF-α) SMD = (-0.51, 95%CI (-0.93, -0.09); p = 0.02), high sensitivity C-reactive protein (hs-CRP) SMD = (-1.06, 95%CI (-1.67, -0.45); p < 0.05) in vitamin D compared to placebo. Additionally, interleukin-6 (IL-6) exhibited a marginal effect SMD = (-0.52, 95%CI (-1.05, 0.01), p = 0.05). Furthermore, a significant reduction in the level of triglycerides SMD = (-0.65, 95%CI (-1.11, -0.18), p < 0.05) was observed, concomitant to a significantly increased high-density lipoprotein (HDL) level SMD = (0.53, 95%CI (0.08, 0.98), p = 0.02). However, no statistically significant changes were observed in total cholesterols SMD = (-0.16, 95%CI (-0.57, 0.24), p = 0.43) and low-density lipoprotein (LDL) SMD = (-0.06, 95%CI (-0.37, 0.24), p = 0.67).

CONCLUSIONS

These findings suggest that vitamin D supplementation may be beneficial in ameliorating inflammation and dyslipidemia in T2D patients.

The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases.

Mechanisms Suggesting a Relationship between Vitamin D and Erectile Dysfunction: An Overview

Vitamin D deficiency (VDD) and erectile dysfunction (ED) heavily burden the male population. The higher prevalence of both conditions in the elderly suggests a possible relationship between the two conditions. In addition, in vitro, animal, and human studies have revealed several mechanisms that may relate VDD to ED. The main mechanism by which vitamin D might exert its action on sexual function appears to be through the regulation of endothelial function. Indeed, VDD correlates with several markers of endothelial function. The action of vitamin D on the endothelium would be exercised both indirectly through its intervention in inflammatory processes and through the production of oxygen free radicals, and directly through the regulation of vascular stiffness, the production of nitric oxide, and the regulation of vessel permeability. Furthermore, the ubiquitous distribution of the vitamin D receptor in the human body means that this hormone can also exert a beneficial effect on erectile function by interfering with those comorbidities significantly associated with ED, such as hypertension, diabetes mellitus, hypercholesterolemia, chronic kidney disease, and hypogonadism. In this review, we thoroughly and carefully presented the evidence and mechanisms that would appear to relate vitamin D levels to erectile function. Furthermore, we have summarized the meta-analytic evidence for and against this association to provide a true representation of this topic. Data published to date suggest that low levels of vitamin D could contribute to worsening erectile function through several mechanisms. Therefore, vitamin D levels should be measured in patients with ED and maintained at adequate levels by specific supplementation in case of deficiency. However, the low quality and heterogeneity of clinical trials evaluating the effects of vitamin D administration on erectile function and ED-associated comorbidities do not allow for a univocal conclusion, and indicate the need for further studies to analyze these aspects.

The Effect of Vitamin D on Inflammation and Dyslipidemia in Type 2 Diabetes Mellitus: Protocol for a Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Type 2 diabetes mellitus is a chronic disease that contributes to an increasing global burden on the health system. It has a high chance of leading to macrovascular complications and cardiovascular disease. As an inflammatory condition, it would be essential to target inflammatory pathways when developing therapeutic drugs for type 2 diabetes mellitus.

OBJECTIVE

We aimed to evaluate the effect of vitamin D on markers of inflammation and lipid profile among adult patients with diabetes.

METHODS

A systematic review will seek studies published on Embase, Google Scholar, PubMed, Web of Science, and Science Direct. This planned systematic review and meta-analysis will be limited to randomized controlled trials; moreover, the search will include published studies regarding the effects of vitamin D on pro-inflammatory cytokines and lipid profiles. The review will include studies published from inception until December 30, 2022. The study identification and selection will be based on the eligibility criteria by 2 independent reviewers. Additionally, a meta-analysis will only be performed if more than 2 studies are available and explore the same outcomes, and this will be analyzed using RevMan (version 5.4.1). The quality and risk of bias will be assessed following the Cochrane risk of bias tool and Jadad checklist.

RESULTS

The process for searching literature review has already started, and this is conducted independently by 2 reviewers using a predefined eligibility and "participants, intervention, comparator, and outcome" criteria. This systematic review and meta-analysis will not require any direct involvement of patients and the public; thus, no ethical approval was required.

CONCLUSIONS

The findings obtained from the proposed study will be presented in scientific seminars, journal clubs, and conferences and published in peer-reviewed journals.

TRIAL REGISTRATION

International Platform of Registered Systematic Review and Meta-analysis Protocols INPLASY202260022; https://inplasy.com/?s=INPLASY202260022.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/42193.

Effects of vitamin D supplementation on the regulation of blood lipid levels in prediabetic subjects: A meta-analysis

This meta-analysis aimed to systematically investigate whether vitamin D supplementation reduces blood lipid—total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglyceride (TG)—levels in prediabetic individuals. Pubmed, Web of Science, Cochrane Library, Embase, CNKI, and WANFANG databases were searched for studies published before 13 February 2022 (including 13 February 2022). Five articles were included. The results showed that vitamin D intervention led to a significant reduction in TG compared with control or placebo treatment (−0.42 [−0.59, −0.25], P &lt; 0.001). Subgroup analyses showed that this effect was particularly significant among the studies that included obese subjects (−0.46 [−0.65, −0.28], P &lt; 0.001), the studies that also included men (not only women) (−0.56 [−0.78, −0.34], P &lt; 0.001), and the studies with intervention durations longer than 1 year (−0.46 [−0.65, −0.28], P &lt; 0.001). Both relatively low doses of 2,857 IU/day (−0.65 [−0.92, −0.38], P &lt; 0.001) and relatively high doses of 8,571 IU/day (−0.28 [−0.54, −0.02] P = 0.04) of vitamin D supplementation reduced TG levels, and the effect was observed both in Northern Europe (−0.65 [−0.92, −0.38], P &lt; 0.001) and Asian (−0.25 [−0.48, −0.03], P = 0.03) country subgroups. No significant effects on TC, HDL-C, and LDL-C were shown. In conclusion, vitamin D supplementation might beneficially affect TG levels in individuals with prediabetes. Particularly longer durations of treatment, more than 1 year, with doses that correct vitamin deficiency/insufficiency, can have a beneficial effect. This meta-analysis was registered at www.crd.york.ac.uk/prospero (CRD42020160780).

Relationship Between Vitamin D Deficiency and Non-alcoholic Fatty Liver Disease: A Cross-Sectional Study From a Tertiary Care Center in Northern India

Background Vitamin D levels are strongly associated with myocardial infarction, coronary artery disease, heart dysfunction, and even mortality. Non-alcoholic fatty liver disease (NAFLD) is a prevalent hepatic illness whose incidence has grown dramatically over the past several decades. Methodology This observational, cross-sectional study was conducted over 1.5 years (January 2019 to June 2020) at the Department of General Medicine of a tertiary care hospital in northern India on 100 adult patients with NAFLD admitted to the emergency ward, intensive care unit, and medical ward. Results In our study, of the 100 patients, 45.0%, 16.0%, and 39.0% of patients exhibited vitamin D deficiency, insufficiency, and sufficiency, respectively. Vitamin D deficiency was the highest among those aged 41-50 (54.2%) and lowest among those aged 30-40 (29.0%). We observed that vitamin D deficiency was less prevalent in people with a normal body mass index (39.1%) than in those who were overweight (91.7%). There was a significant (p < 0.05) association between the severity of vitamin D deficiency and the presence of hepatomegaly, splenomegaly, and ascites. Overall, the incidence of fatty liver was 49% among patients. There was a significant (p = 0.0001) correlation between fatty liver and serum vitamin D levels. The association between the proportion of patients with fatty liver and the degree of vitamin D deficiency was found to be significant (p = 0.04). The relationship between the distribution of patients according to insulin resistance and the degree of vitamin D deficiency was also statistically significant (p < 0.001). Conclusions Vitamin D deficiency is associated with an increased risk of NAFLD, as well as with the severity of NAFLD.

Effect of Vitamin D and/or Calcium Supplementation on Pancreatic β-Cell Function in Subjects with Prediabetes: A Randomized, Controlled Trial

So far, the potential role of vitamin D in β-cell function remains a matter of debate. Therefore, a randomized, placebo-controlled trial (RCT) was conducted to evaluate the effect of a vitamin D supplement with or without calcium on β-cell function in a Chinese population with prediabetes. Two hundred and forty-three subjects were randomly assigned in a 2-by-2 factorial-design RCT to receive either 1600 IU/day vitamin D₃ with/or 500 mg/day calcium for 24 weeks. The results showed that oral administration of vitamin D and calcium could increase the secretion of insulin. Vitamin D-insufficient individuals displayed an increment in the disposition index (adjusted change = 0.31, 95%CI: 0.07, 0.56) after treatment by vitamin D + calcium. It illustrated that supplementation with vitamin D and calcium might improve the function of pancreatic β-cell in prediabetes with low serum 25(OH)D levels. However, further studies are needed to confirm the findings. Given the low vitamin D content in natural foods, it is necessary to fortify processed foods with vitamin D.

Comparison of Serum Vitamin D Levels with Glucose, Lipid, and the Other Biochemical Parameters: A Cross-Sectional Study

"Since vitamin D is synthesized from cholesterol, it is claimed to be associated with insulin resistance, suggesting that there may be an association between vitamin D glucose and lipids. For this reason, we aimed to investigate a relationship between vitamin D and biochemical parameters, including glucose and lipids. This cross-sectional study included 198 patients .admitted to the family medicine outpatient clinic between June and December 2016. There was no significant correlation between vitamin D and serum glucose, total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol, calcium, magnesium, sodium, TSH, and body mass index values in both men and women. There was a correlation between vitamin D and total cholesterol and LDL cholesterol levels in the younger subjects below 41 years (p=0.002). Regression analysis with other variables showed no statistical significance between vitamin D levels on LDL-C levels (P=0.309). Despite previous studies, our study did not confirm the effects of vitamin D on serum glucose, lipid, calcium, and other biochemical parameters. However, these results suggest that the standard up-to-date literature showing the relationship between vitamin D and various metabolic and hormonal disorders may need to be confirmed by new large-scale studies. "

Effects of long-term vitamin D supplementation on metabolic profile in middle-aged and elderly patients with type 2 diabetes

To evaluate the effects of long-term vitamin D supplementation on metabolic profiles in middle-aged to elderly patients with type 2 diabetes (T2D), a randomized controlled trial was conducted among patients with T2D aged 50-70 years. A total of 270 patients underwent randomization with 135 being allocated to the vitamin D group and 135 to the control group, and participants in the vitamin D group received oral vitamin D₃ (800 IU/day) for 30 months. Serum 25(OH)D and metabolic variables were measured at baseline, and after 6, 12, 18, and 30 months of intervention. After 30 months, the vitamin D group showed a greater increase in serum 25(OH)D than the control group (12.39 ± 6.99 vs 5.35 ± 5.29 ng/ml, P < 0.001). Meanwhile, changes in the levels of fasting insulin, HOMA-IR, non-high-density-lipoprotein cholesterol (non-HDL-C), high-sensitivity C-reactive protein (hs-CRP), and uric acid differed significantly between the two groups (all P < 0.05). Stratified analysis indicated that change in uric acid differed significantly between the two groups in subgroup with baseline 25(OH)D ≥ 20 ng/ml (P = 0.042) or subgroup with female patients (P = 0.034). And the change in fasting blood glucose (FBG) differed significantly between the vitamin D group (-0.30 ± 2.52 mmol/L) and the control group (0.49 ± 1.78 mmol/L, P = 0.049) among patients achieving 25(OH)D concentrations of 30 ng/ml at the end of this trial. A significant difference in the change of triglyceride was observed between the two groups among patients with obesity at baseline [0.05(-0.59, 0.23) vs 0.41(-0.01, 0.80) mmol/L, P = 0.023]. These findings suggested that long-term vitamin D supplementation significantly reduced fasting insulin, HOMA-IR, and serum concentrations of non-HDL-C, hs-CRP, and uric acid among middle-aged to elderly patients with T2D. And vitamin D status, gender, and baseline obesity may modify the effects of vitamin D supplementation.

Efficacy of vitamin D supplementation on child and adolescent overweight/obesity: a systematic review and meta-analysis of randomized controlled trials

The global prevalence of overweight and obesity in children and adolescents has been increasing. Child and adolescent overweight/obesity has been demonstrated to be partially associated with vitamin D deficiency. This systematic review and meta-analysis aims to assess the efficacy of vitamin D supplementation on child and adolescent overweight/obesity. PubMed, Embase, Cochrane Library, and Web of science were searched from inception to June 20th, 2022. Randomized controlled trials (RCTs) assessing the efficacy of vitamin D on child and adolescent overweight/obesity were included. The Cochrane bias risk assessment tool was used to assess the bias risk of included studies, and subgroup analysis was conducted based on different administration dosages. All data-analyses were performed using R 4.2.1. There were 1502 articles retrieved, and 10 eligible studies were finally included, with a total of 595 participants. Meta-analysis showed no differences in LDL, TC, TG, BMI, ALP, Ca, and PTH between vitamin-D (Vit-D) group and placebo, while Vit-D group resulted in improved HOMA-IR[WMD =  - 0.348, 95%CI (- 0.477, - 0.219), p = 0.26]. Subgroup-analysis showed no significant difference in the increase of 25-(OH)-D between subgroups (p = 0.39), whereas the serum 25-(OH)-D level was increased under different Vit-D doses [WMD = 6.973, 95%CI (3.072, 10.873)]. High daily dose (≥ 4000 IU/d) of Vit-D might decrease CRP and increase HDL levels.   Conclusion: High dose of Vit-D supplementation (over 4000 IU/d) would reduce several cardiometabolic risk indicators and improve insulin resistance. More high-quality and large-scale RCTs are needed to provide more robust evidence. What is Known: • Vit-D deficiency is common in overweight/obesity (OW/OB) children and adolescents. • Previous randomized studies on the benefit of Vit-D supplementation to OW/OB children and adolescents are inconsistent. What is New: • This is the first meta-analysis conducted to assess the efficacy of Vit-D supplementation on child and adolescent OW/OB. • High dose of Vit-D supplementation is beneficial to cardiovascular metabolism, and improve insulin resistance on child and adolescent OW/OB.

Association between metabolic body composition status and vitamin D deficiency: A cross-sectional study

This study aimed to investigate the risk of vitamin D deficiency in a relatively healthy Asian population, with (i) metabolically healthy normal weight (MHNW) (homeostasis model assessment-insulin resistance [HOMA-IR] < 2. 5 without metabolic syndrome [MS], body mass index [BMI] < 25), (ii) metabolically healthy obesity (MHO) (HOMA-IR < 2.5, without MS, BMI ≥ 25), (iii) metabolically unhealthy normal weight (MUNW) (HOMA-IR ≥ 2.5, or with MS, BMI < 25), and (iv) metabolically unhealthy obesity (MUO) (HOMA-IR ≥ 2.5, or with MS, BMI ≥ 25) stratified by age and sex. This cross-sectional study involved 6,655 participants aged ≥ 18 years who underwent health checkups between 2013 and 2016 at the Chang Gung Memorial Hospital. Cardiometabolic and inflammatory markers including anthropometric variables, glycemic indices, lipid profiles, high-sensitivity C-reactive protein (hs-CRP), and serum 25-hydroxy vitamin D levels, were retrospectively investigated. Compared to the MHNW group, the MHO group showed a higher odds ratio (OR) [1.35, 95% confidence interval (CI) 1.05-1.73] for vitamin D deficiency in men aged < 50 years. By contrast, in men aged > 50 years, the risk of vitamin D deficiency was higher in the MUO group (OR 1.44, 95% CI 1.05-1.97). Among women aged < and ≥ 50 years, the MUO group demonstrated the highest risk for vitamin D deficiency, OR 2.33 vs. 1.54, respectively. Our study revealed that in women of all ages and men aged > 50 years, MUO is associated with vitamin D deficiency and elevated levels of metabolic biomarkers. Among men aged < 50 years, MHO had the highest OR for vitamin D deficiency.

Effect of serum vitamin D on metabolic associated fatty liver disease: a large population-based study

BACKGROUND

Several studies have revealed that serum vitamin D is an important factor for metabolic associated fatty liver disease (MAFLD), but there had been no consistent conclusion.

METHODS

Of 427,507 subjects who underwent health examination, 83,625 who met the inclusion criteria were included in a cross-sectional analysis. Clinical and laboratory data were collected for analysis. MAFLD was diagnosed by abdominal imaging.

RESULTS

Multivariate linear regression models discovered a negative association between serum vitamin D and MAFLD (OR: 0.92, 95% CI: 0.90 to 0.94, p = .001), after adjusting for other well-identified risk factors. The same result was found when serum vitamin D was handled as a categorical variable (quartile, Q1-Q4) (Q4 vs. Q1, OR: 0.82, 95% CI: 0.77 to 0.87, p < .001), and a significant linear trend was observed (p for trend <.001). After analysis, a nonlinear relationship was detected between serum vitamin D and MAFLD, with an inflection point of 2.23 (44.6 nmol/L or 17.84 ng/mL). The effect sizes and the confidence intervals on the left and right sides of the inflection point were 1.16 (1.06 to 1.28) and 0.89 (0.86 to 0.91), respectively. All interactions with MAFLD were not significant for age, sex, diabetes, hypertension, smoking and body mass index (p for interaction = .110, .558, .335, .195, .616 and .401, respectively).

CONCLUSIONS

There was a nonlinear relationship between serum vitamin D and MAFLD. When the serum vitamin D level was ≥44.6 nmol/L (17.84 ng/mL), a negative correlation between serum vitamin D and MAFLD was detected. Below this level, serum vitamin D might promote the progression of MAFLD.

Effect of vitamin D supplementation on cardiac-metabolic risk factors in elderly: a systematic review and meta-analysis of clinical trials

BACKGROUND

There has been a longstanding interest in the potential effect of vitamin D in preventing cardiac-metabolic diseases. However, there are divergent results regarding the impact of vitamin D supplementation (VDS) on managing cardiac-metabolic outcomes in the elderly population.

MATERIAL AND METHOD

We systematically searched electronic databases; Web of Science, PubMed, Scopus, EMBASE, Cochrane, and ProQuest. We included all trials that evaluated the effect of VDS on cardiac-metabolic risk factors in the elderly population, which were published until 30 September 2021. The effects of VDS on cardiac-metabolic outcomes were assessed using standardized mean difference (SMD). A random-effect model was used to pool the SMD and 95% confidence interval (CI).

RESULT

The literature search identified 4409 studies, of which 12 trials met inclusion criteria. Results of random effect meta-analysis indicated a significant reduction in total cholesterol (TC) (SMD: - 0.14 mg/dl; 95% CI: - 0.25, - 0.02) and triglyceride (TG) (SMD: - 0.45 mg/dl; 95% CI: - 0.86, - 0.04) with VDS compared to the placebo. The subgroup analyses revealed that the reduction of TG in patients with diabetes and vitamin D deficiency was significant. Furthermore, short-term intervention (≤ 6 months) induced a significantly lower level of TG and insulin in comparison to longer duration (> 6 months).

CONCLUSION

The study suggests that VDS could improve insulin concentration and dyslipidemia in the elderly population. The systematic review was registered in Alborz university of medical sciences with 2060-01-03-1397 number and the Ethics council IR.ABZUMS.REC.1397.207 number.

Vitamin D3 intake as modulator for the early biomarkers of myocardial tissue injury in diabetic hyperlipidaemic rats

CONTEXT

Myocardial cell death occurs within hours following the onset of myocardial ischaemia and its chief cause is atherosclerosis. There is a link between vitamin D3 deficiency and many cardiovascular risk factors.

OBJECTIVE

This study compared the effect of vitamin D3 on early biomarkers of myocardial injury, to that of atorvastatin.

METHODS

Diabetic hyperlipidaemia was induced in Wistar rats, which were divided into 3 groups: diabetic hyperlipidaemic control, diabetic hyperlipidaemic rats treated with atorvastatin and diabetic hyperlipidaemic rats treated with vitamin D3. Blood glucose, glycated haemoglobin and lipid profile were evaluated. Markers of myocardial injury were examined including cardiac troponin, heart fatty acid binding protein (HFABP) and C-terminal pro-endothelin-1 (CT-pro-ET-1).

RESULTS

Vitamin D3 and atorvastatin intake improved lipid profile and glucose homeostasis, and reduced levels of predictive biomarkers of myocardial injury.

CONCLUSION

Vitamin D3 can be used in a suitable dose as a safe and protective candidate against myocardial injury.

Vitamin D and cardiovascular disease risk. A literature overview

BACKGROUND

Atherosclerosis and cerebro and cardiovascular disease associated represent the major cause of morbidity and mortality worldwide. Recently, vitamin D deficiency has been considered a new potential risk factor of these conditions.

METHODS AND RESULTS

In this reviw we briefly describe the biological role of vitamin D, analyze the pathophysiological associations between cardiovascular disease and vitamin D, summarize and synthesize the evidence from literature about the association between vitamin D and cardiovascular disease.

RESULTS

Vit D is an essential vitamin for bone metabolism and homeostasis. The maintenance of optimal blood levels contributes to the correct homeostasis by influencing different metabolic processes, including those underlying cardiovascular diseases. However, the evidence does not support vitamin D routine administration for the prevention and treatment of cardiovascular disease and intake to achieve specific cardiovascular effects. Evidence shows that maintaining optimal levels of vitamin D, ensures cardiovascular protection.

Use of zoledronic acid in antiosteoporosis treatment is associated with a decreased blood lipid level in postmenopausal women with osteoporosis: A cohort study in China

OBJECTIVE

: This cohort study aimed to evaluate the protective effects of zoledronic acid (ZA) in lipidemia in postmenopausal women with osteoporosis.

METHODS

A total of 668 postmenopausal women with osteoporosis were regularly followed up for 12 months between January 2018 and August 2021 in the department of endocrinology and the health examination center of the hospital. They were included in this cohort study. They were divided into group I and group II depending on lipid metabolism disorder; Group II received atorvastatin 20 mg/d orally. Groups I and II, divided into experimental group (ZA exposure) and control group (ZA nonexposure), depending on treatment with or without ZA. All the data were collected from the hospital's medical record system and passed ethical review.

RESULTS

In group I, which was the ZA exposure group(n = 164), the level of low-density lipoprotein cholesterol (LDL-C) was significantly lower than that before ZA treatment(P = 0.017); in the ZA nonexposure group(n = 158), the levels of LDL-C, total cholesterol (TC) and triglycerides (TG) significantly increased after 12 months of follow-up, (P = 0.005, P < 0.001 and P = 0.001). At the baseline, no significant difference was found in blood lipid indicators between the ZA exposure and nonexposure groups (P > 0.05), but the levels of LDL-C and TC in the exposed group significantly decreased after 12 months of follow-up, (P = 0.008 and P = 0.027). Also, the ZA exposure group had 47 new cases of lipid metabolism disorder, while the nonexposure group had 43 new cases of lipid metabolism disorder after 12 months of follow-up. In group II, which was the ZA exposure group(n=155), the levels of LDL-C and TC were significantly lower than those before ZA treatment(P < 0.001 and P < 0.001). At the baseline, the ZA exposure and nonexposure groups(n = 191), had no significant difference in blood lipid indicators (P > 0.05), but the levels of LDL-C and TC significantly decreased in the exposed group after 12 months of follow-up, (P < 0.001 and P = 0.003).

CONCLUSION

This cohort study found that ZA might exert a protective effect on lipid metabolism in postmenopausal women with osteoporosis. In postmenopausal women with lipid disorders suffering from osteoporosis, the treatment with ZA combined with atorvastatin or ZA alone significantly reduced the level of blood lipid (especially LDL-C and TC) compared with atorvastatin alone.

Evidence of a Causal Relationship Between Vitamin D Status and Risk of Psoriasis From the UK Biobank Study

Background

Plenty of observational studies suggested that vitamin D concentrations were associated with psoriasis, but the causality of this relationship was elusive.

Objective

To investigate the causal relationship between vitamin D and psoriasis.

Methods

Cox proportional hazard model was used to investigate the association between vitamin D status and psoriasis in a prospective cohort study from UK Biobank. Single nucleotide polymorphisms (SNPs) that are strongly associated with circulating 25OHD were constructed as instrumental variables in Mendelian randomization (MR) to determine the causality between vitamin D and psoriasis.

Results

During a median follow-up of 10.99 years, we identified 2,856 participants with incident psoriasis. The prospective cohort study demonstrated individuals with 25OHD deficiency (< 25 nmol/L) at baseline were associated with approximately 20% increased risk of incident psoriasis in different categories of sex, age, and body mass index (BMI) after adjusting for covariates. The largest effect size was observed in the obese group (BMI > 30 kg/m²), as 25OHD deficiency presented with 30% additional risk of incident psoriasis compared to those with 25OHD > 50 nmol/L (HR = 0.701; 95% CI: 0.583-0.843; p < 0.001). Additionally, 69 independent SNPs associated with circulating 25OHD level were selected for the MR analysis, and the result suggested that genetically predicted one standard deviation (SD) increment in log-transformed 25OHD was associated with 24% decreased risk of psoriasis (OR = 0.76; 95% CI: 0.60-0.98, p = 0.020).

Limitations

The association of 25OHD and severity of psoriasis could not be estimated in the current study.

Conclusion

The combined prospective and MR analysis additionally provided evidence that the epidemiologically and genetically determined level of 25OHD conferred an increased risk of psoriasis.

Targeting dyslipidemia with antioxidative vitamins C, D, and E; a systematic review of meta-analysis studies: Dyslipidemia and antioxidative vitamins

Background

There is controversial evidence for the beneficial effects of antioxidative vitamins (vits) on dyslipidemia. In this regard, we aimed to systematically review all meta-analyses of trials on this topic.

Methods

We comprehensively searched PubMed, Web of Science, Scopus, and Cochrane Library databases until January 2021 to explore the published English meta-analyses of trials conducted to assess the effects of single or combined vits C, D and E consumption on lipid profile. The meta-analyses of observational, in vivo/in vitro, or case-report studies were excluded. Search results were reported based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flowchart.

Results

Overall, 25 meta-analyses including 32,177 individuals with different underlying disorders met our inclusion criteria. Numerous studies had assessed supplementation with Vit-D or its combination with other agents on lipid profile. Consumption of 400 IU/day (d) to 50,000 IU/week (w) Vit-D for at least eight weeks improved the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) in type 2 diabetes mellitus or polycystic ovary syndrome (PCOS) patients. This treatment reduced the levels of TC and TG in patients with chronic kidney disease. A significant increase in high-density lipoprotein cholesterol (HDL-C) levels was only observed in coronary artery disease patients. Sole intake of 500-2000 mg/d Vit-C for at least 3 weeks improved LDL-C and TG values in hypercholesterolemic patients. Nevertheless, sole intake of Vit-E had controversial effects on lipid profile. The combination of 400-1800 IU/d omega-3 free fatty acid (FFA) and 400 IU/d Vit-E significantly reduced the levels of LDL-C and TG in overweight individuals, without any significant effect on other components. A significant improvement of TG values was observed after consumption of 1000-2000 mg/d omega-3 FFA plus 400 IU/d Vit-E along with 50,000 IU/each 2w Vit-D for at least 6 weeks in diabetic patients.

Conclusion

The beneficial effects of antioxidative vitamins (C, D, E) or their combination with other agents on lipid profile varied based on their dosage, intake duration, and the health status of the individuals.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00919-8.

Association of serum 25-Hydroxy Vitamin D level with lipid, lipoprotein, and apolipoprotein level

Introduction 25-Hydroxy vitamin D (Vit D3) deficiency was found to be associated with vascular dysfunction, arterial stiffening, extent of coronary artery disease and cardiovascular mortality. Previous studies showed positive correlation between serum Vit D3 and HDL-C and negative correlation between Vit D3 and LDL-C. The aim of this study is to investigate more details about the possible association of serum Vit D3 level with lipid, lipoprotein and apolipoprotein level. Methods Totally 101 patients were included in this study and Vit D3, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), High-density lipoprotein cholesterol (HDL-C), total triglyceride (TG), non-high-density lipoprotein cholesterol (Non-HDL-C), low-density lipoprotein particle (LDL-P), small dense low-density lipoprotein particle (sLDL-P), small dense low-density lipoprotein cholesterol (sdLDL-C), High-density lipoprotein cholesterol particles (HDL-P), High-density lipoprotein 2-cholesterol (HDL2-C), Apolipoprotein B(ApoB), Apolipoprotein A1 (Apo A1) and Apolipoprotein B/Apolipoprotein A1 ratio (ApoB/A ratio) were tested. Results Our results show that patients with Vit D3 deficiency (Vit D3 < 30 ng/ml) have significantly higher level of LDL-C, TG, Non-HDL-C, LDL-P, sLDL-P, sdLDL-C, ApoB and ApoB/A ratio compare with patients have normal Vit D3 level (Vit D3 > 30 ng/ml). Patients with normal Vit D3 level have significantly higher level of HDL-C and HDL2-C. Correlation study shows that Vit D3 level is negative correlated with TC, LDL-C, TG, Non-HDL-C, LDL-P, sLDL-P, sdLDL-C, ApoB and ApoB/A ratio and positive correlated with HDL2-C level. Conclusion Our results show that Vit D3 deficiency links to an increased risk for dyslipidemia and that may be the reason that patients with vitamin D deficiency tend to have higher risk of coronary artery disease.

Association of changes in lipid levels with changes in vitamin D levels in a real-world setting

In clinical trials, vitamin D supplementation has been reported to reduce serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) but not high-density lipoprotein cholesterol (HDL-C). In this cohort study we evaluated the association between changes in vitamin D (25-hydroxyvitamin D) and changes in lipid levels in a real-world setting. Changes in lipid levels over a 1-year period were evaluated among individuals whose vitamin D levels increased (group 1) or decreased (group 2) by ≥ 10 ng/mL in year 2018 versus 2017 (cohort 1; n = 5580), in 2019 versus 2018 (cohort 2, n = 6057), or in 2020 versus 2019 (cohort 3, n = 7249). In each cohort, levels of TC, LDL-C, and TG decreased in group 1 and increased in group 2. Between-group differences in average changes in the 3 cohorts ranged from 10.71 to 12.02 mg/dL for TC, from 7.42 to 8.95 mg/dL for LDL-C, and from 21.59 to 28.09 mg/dL for TG. These differences were significant after adjusting for age, sex, race, education, body mass index, blood pressure, smoking status, geographical location, and baseline levels of vitamin D and lipids (P < 0.001). Changes in vitamin D levels were not significantly associated with changes in HDL-C levels.

Effect of vitamin D supplementation on markers of cardiometabolic risk in children and adolescents: A meta-analysis of randomized clinical trials

BACKGROUND AND AIMS

An increasing attention to the effect of vitamin D supplementation on cardiometabolic risk markers in children and adolescents has been gained recently. However, the results are inconsistent. Therefore, we conducted a meta-analysis to examine the effect of vitamin D supplementation on cardiometabolic risk markers in children and adolescents.

METHODS AND RESULTS

Eligible randomized controlled trials (RCTs) were identified by searching PubMed, EMBASE and Web of Science. The results of this study are synthetized and reported in accordance with the PRISMA statement. GRADE system was used to assess the certainty of evidence. A total of 9 RCTs were identified and included in the meta-analysis. We found that vitamin D supplementation did not affect the changes of cardiometabolic risk markers including high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), body mass index (BMI), waist circumferences, systolic blood pressure (SDP) and diastolic blood pressure (DBP). However, vitamin D supplementation showed a beneficial effect on fasting glucose (MD, -1.54 mg/dl, 95% CI -2.98 to -0.10) and TG (MD, -24.76 mg/dl, 95% CI -37.66 to -11.86) in the sub-group analysis of total vitamin D supplementation ≥ 200,000 IU.

CONCLUSIONS

Vitamin D supplementation appeared to have a beneficial effect on reducing fasting glucose and TG level when total vitamin D supplementation ≥200,000 IU but not HDL-C, LDL-C TC, blood pressure and waist circumferences levels in children and adolescents. Further studies are needed to address this issue.

Effect of Spirulina Supplementation on Systolic and Diastolic Blood Pressure: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Spirulina is a microalga that presents various important pro-health properties, for instance lowering blood pressure in the research. The study aims to appraise the efficacy of Spirulina administration on systolic (SBP) and diastolic blood pressure (DBP). Randomized controlled trials (RCTs) were retrieved by a systematic search of PubMed, Web of Science, and the Cochrane Library databases from inception to June 2021 according to a standardized protocol. The effect size of each study was counted from mean and standard deviation before and after the intervention and shown as Un-standardized mean difference and 95% confidence interval. Sensitivity analyses were performed. Meta-analysis on 5 RCTs with 230 subjects was eligible. The amount of Spirulina ranged from 1 to 8 g per day, and intervention durations ranged from 2 to 12 weeks. Data analysis indicated that Spirulina supplementation led to a significant lowering of SBP (Mean Difference (MD): -4.59 mmHg, 95% Confidence Interval (CI): -8.20 to -0.99, I square statistic (I²) = 65%) and significant lowering of DBP (MD: -7.02 mmHg, CI: -8.86 to -5.18, I² = 11%), particularly in a subgroup of hypertensive patients. Spirulina administration might have a supportive effect on the prevention and treatment of hypertension. More exact randomized controlled trials are needed to clarify the effect of Spirulina supplementation on blood pressure.

Early 1,25-Dihydroxyvitamin D3 Supplementation Effectively Lowers the Incidence of Type 2 Diabetes Mellitus via Ameliorating Inflammation In KK-Ay Mice

Few studies have been performed to investigate the effect of vitamin D supplementation and T2DM in type 2 diabetic animal models. The present study aimed to explore the relationship between early 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] and the incidence of T2DM and determine whether early 1,25(OH)₂D₃ supplementation was associated with inflammation in KK-A^y mice. The KK-A^y mice were divided into 4 vitamin D treatment groups, the low-dose vitamin D supplementation group (VDS-L, 1.5 μg/kg 1,25(OH)₂D₃), moderate-dose vitamin D supplementation group (VDS-M, 3.0 μg/kg 1,25(OH)₂D₃), high-dose vitamin D supplementation group (VDS-H, 6.0 μg/kg 1,25(OH)₂D₃) and the model control group (MC). C57BL/6J mice were used as the controls. The treatment period lasted for 9 wk. During this treatment period, fasting blood glucose (FBG) level of the mice was measured on a weekly basis. The levels of lipid profile, insulin and inflammation biomarkers were determined after 9 wk of 1,25(OH)₂D₃ intragastric gavage. After 9 wk of 1,25(OH)₂D₃ intragastric gavage, FBG level was significantly decreased in the vitamin D treatment groups compared with the MC group. The number of T2DM incidence in the VDS-L group (n=7), VDS-M group (n=5) and VDS-H group (n=3) was lower than those in the MC group (n=10) on week 9. Moreover, serum C-reactive protein (CRP) and interleukin-6 (IL-6) in the vitamin D treatment groups were significantly suppressed by 1,25(OH)₂D₃ administration compared with the MC group. Early 1,25(OH)₂D₃ supplementation could effectively lower the incidence of T2DM via ameliorating inflammation in KK-A^y mice.

Serum vitamin D levels in relation to metabolic syndrome: A systematic review and dose-response meta-analysis of epidemiologic studies

Several epidemiological studies examined the association of serum vitamin D with metabolic syndrome (MetS), but the findings were inconsistent. We conducted a systematic review and dose-response meta-analysis to quantify the association between blood vitamin D levels and MetS in adults. A systematic search up to December 2020 was conducted in MEDLINE (PubMed), ISI (Web of Science), Scopus, and Google Scholar databases for epidemiological studies that assessed the relation of serum 25-hydroxyvitamin D (as the exposure) and MetS (as the outcome) in adults. Eligible cross-sectional studies were restricted to those with representative populations. Finally, 43 studies were included in the analysis (38 cross-sectional, one nested case-control, and four cohorts studies). Combining 41 effect sizes from 38 cross-sectional studies included 298,187 general adult population revealed that the highest level of serum vitamin D, compared with the lowest level, was significantly related to a 43% decreased odds of MetS in developed countries (odds ratio [OR]: 0.57; 95% confidence interval [CI]: 0.49-0.65) and 40% in developing countries (OR: 0.60; 95% CI: 0.52-0.70). Linear dose-response analysis (including 222,175 healthy individuals and 39,308 MetS patients) revealed that each 25 nmol/L increase in serum vitamin D level was significantly associated with a 15% decreased odds of MetS (OR: 0.85; 95% CI: 0.80-0.91); however, we found no significant nonlinear association. Meta-analysis of five prospective studies with 11,019 participants revealed no significant relation (relative risk [RR]: 0.70; 95% CI: 0.37-1.32). This meta-analysis indicated an inverse association between serum vitamin D concentrations and risk of MetS in general adult populations in cross-sectional studies in a dose-response manner. However, no significant association was found in a small number of cohorts. More prospective studies are needed to confirm the causality of this relationship.

Effect of 1-year oral cholecalciferol on a metabolic profile and blood pressure in poor-controlled type 2 diabetes mellitus: an open-label randomized controlled pilot study

PURPOSE

Hypovitaminosis D has been associated with many cardio-metabolic disorders, although their pathogenetic link still remains unclear. Our aim was to evaluate whether 1-year vitamin D (D) supplementation could improve glycemic control, lipid profile, systolic (SBP) and diastolic (DBP) blood pressure levels and body composition.

METHODS

In an open-label randomized-controlled pilot study, thirty poor-controlled (HbA1c > 59 mmol/mol) type 2 diabetic patients (age 71.5 ± 3.2 years, M/F 21/9, BMI 29.8 ± 3.6 kg/m²) with hypovitaminosis D (25OHD 22.0 ± 11.3 nmol/l) were randomized to cholecalciferol supplementation (500 UI/kg p.o. weekly, + D) or observation (- D) for one year. Changes in parameters of glucose, lipid and blood pressure control at 3, 6, 9 and 12 months vs. baseline were assessed.

RESULTS

One-year D supplementation restored D status and had a beneficial effect on fasting glucose (FG, mean percentage changes ± SD, - 1.8% ± 23.1 vs. + 18.8% ± 30.0), glycosylated haemoglobin (HbA1c, - 13.7% ± 14.5 vs. - 4.2% ± 14.1), SBP (- 13.4% ± 8.5 vs. - 2.4% ± 12.6) and HDL-cholesterol levels (- 2.1% ± 14.0 vs. - 10.9% ± 12.9; p < 0.05 for all comparisons) in + D vs. - D patients, respectively. In the former, a reduction in HBA1c, SBP and DBP levels, BMI, fat mass index (FMI) and ratio (FMR) was observed after 1 year (p < 0.05 for all comparisons vs. baseline). We noticed a relationship between 1-year mean percentage changes of serum 25OHD and SBP levels (R = - 0.36, p < 0.05).

CONCLUSION

One-year cholecalciferol supplementation, able to restore D status, significantly improves FG, HbA1c, SBP and HDL-cholesterol levels in patients with poor-controlled type 2 diabetes mellitus and D deficiency.

Use of GRADE in evidence syntheses published in high-impact-factor nutrition journals: A methodological survey

OBJECTIVE

To identify and describe the use of the GRADE approach for rating the certainty of evidence in nutrition systematic reviews (SRs).

STUDY DESIGN AND SETTING

We systematically searched for SRs using GRADE that were published between 2015 and 2019 in the 10 "nutrition" journals with the highest impact factor according to the JCR 2018.

RESULTS

Out of 800 SRs, 55 SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Forty-seven SRs (5.9%) rated the outcome specific certainty of evidence (n = 36 in 2018/2019). We identified a total of 465 certainty of evidence outcome ratings (n = 335 RCT ratings), ranging from very-low (28.8%) to low (41%), moderate (26.5%), and high (3.7%). Very-low and high certainty of evidence ratings accounted for 61.4% and 0.8% of ratings in SRs of NRSs, compared to 16.1% and 4.8% in SRs of RCTs. Certainty of evidence was downgraded mostly for risk of bias (37.8%) and imprecision (33%) in SRs of RCTs and for imprecision (32.7%), risk of bias (29.4%) and inconsistency (29%) in SRs of NRSs.

CONCLUSION

Our study suggests a need for directing more attention toward strengthening acceptance of GRADE as well as building knowledge of the GRADE methodology in nutrition evidence synthesis.

The Effects of Vitamin D Supplementation on Metabolic and Oxidative Stress Markers in Patients With Type 2 Diabetes: A 6-Month Follow Up Randomized Controlled Study

Vitamin D deficiency could play an important role in the pathogenesis of type 2 diabetes mellitus (T2DM) as it may alter several crucial processes in the development of diabetes and its complications, such as pancreatic insulin secretion, peripheral insulin resistance, persistence of systemic "sterile" inflammation and immune activation. Vitamin D may also have an antioxidant effect through the inhibition of free radicals generation. The reported study was designed with eligible consecutively recruited patients with T2DM on standard metformin therapy (n=130), randomized in 1:1 ratio, considered to have undergone Vitamin D supplementation according to the guidelines proposed by the Endocrine Society, or to have continued with metformin only. The potential benefit was monitored through the influence on glycemia level, glycated haemoglobin (HbA1c), insulin resistance index (calculated as homeostatic model assessment; HOMA-IR), Castelli Risk Index I and Tryglicerides/Thiobarbituric acid-reactive substances (TG/TBARS) Index in a 6-month follow up period. Our study indicates that oral daily doses of vitamin D improve HbA1c levels over the 3-month and 6-month period, followed by a significant decrease in advanced oxidation protein products levels over the 3-month period when higher vitamin D doses are given. The effect of vitamin D on HOMA-IR index, malondialdehyde levels and TG/TBARS index was not statistically significant. Further investigation should consider defining the doses of vitamin D in patients with T2DM which may attenuate the oxidative stress risk, the risk of metabolic syndrome and the risk of related cardiovascular events.

Exploring the effect of vitamin D3 supplementation on surrogate biomarkers of cholesterol absorption and endogenous synthesis in patients with type 2 diabetes-randomized controlled trial

BACKGROUND

Inverse associations have been reported between serum 25-hydroxyvitamin D [25(OH)D] and circulating cholesterol concentrations in observational studies. Postulated mechanisms include reduced bioavailability of intestinal cholesterol and alterations in endogenous cholesterol synthesis.

OBJECTIVE

To explore the effect of daily supplementation with 4000 IU/d vitamin D3 for 24 wk on surrogate biomarkers of cholesterol absorption (campesterol and β-sitosterol) and endogenous synthesis (lathosterol and desmosterol).

METHODS

Ancillary study of The Vitamin D for Established Type 2 Diabetes (DDM2) trial. Patients with established type 2 diabetes (N = 127, 25-75 y, BMI 23-42 kg/m2) were randomly assigned to receive either 4000 IU vitamin D3 or placebo daily for 24 wk. Of participants without changes in cholesterol-lowering medications (n = 114), plasma surrogate cholesterol absorption and endogenous synthesis biomarker concentrations were measured and merged with available measures of serum LDL cholesterol and HDL cholesterol concentrations.

RESULTS

At week 24, vitamin D3 supplementation significantly increased 25(OH)D concentrations (+21.5 ± 13.4 ng/mL) but not insulin secretion rates (primary outcome of the parent study) as reported previously. In this ancillary study there was no significant effect of vitamin D3 supplementation on serum cholesterol profile or surrogate biomarkers of cholesterol absorption and endogenous synthesis. Compared with participants not treated with cholesterol-lowering medications, those who were treated exhibited a greater reduction in plasma campesterol concentrations in the vitamin D3 but not placebo group (P-interaction = 0.011). Analyzing the data on the basis of cholesterol absorption status (hypo- versus hyperabsorbers) or cholesterol synthesis status (hypo- versus hypersynthesizers) did not alter these results.

CONCLUSIONS

Vitamin D3 supplementation for 24 wk had no significant effect on surrogate biomarkers of cholesterol absorption or endogenous synthesis, consistent with the lack of effect on serum cholesterol profile. Vitamin D3 supplementation resulted in greater reduction in campesterol concentrations in participants not using compared with those using cholesterol-lowering medications. Further studies are required.This trial was registered at clinicaltrials.gov as NCT01736865.

Vitamin D supplementation effects on the clinical outcomes of patients with coronary artery disease: a systematic review and meta-analysis

In this systematic review and meta-analysis our aim was to assess the effect of vitamin D supplementation on cardiac outcomes in patients with coronary artery disease (CAD). The search terms were performed from January 2000 to January 2018, only randomized clinical trials (RCT) in human subjects were considered, with no language restrictions. The electronic databases used in this study were: PubMed; Cochran library; Embase; and Scopus. Two independent expert reviewers carried out data extraction according to Cochrane recommendations. Only four RCTs were found in relation to the effects of vitamin D supplementation on the coronary artery disease. In these 299 patients, vitamin D supplementation had significant favorable effects on Diastolic Blood Pressure (DBP) (- 2.96, p = 0.02) and Parathyroid hormone (PTH) (- 4.05, p < 0.001). However, it had no significant effects on hs-CRP mean difference (- 0.04, p = 0.25), total cholesterol (TC) (- 0.46, p = 0.83), triglyceride (TG) (0.68, p = 0.89), low-density lipoproteins (LDL) (2.08, p = 0.56), and high-density lipoproteins (HDL) (- 2.59, p = 0.16). In conclusion, the use of vitamin D was associated with improvements in some cardiac outcomes of CAD patients with vitamin D deficiency. Also, further research is needed to clarify these results.

Vitamin D status affects the relationship between lipid profile and high-sensitivity C-reactive protein

Background

The biological pathways through which vitamin D is involved in the regulation of systemic inflammation remain largely unknown.

Objective

The objective of this study was to evaluate the role of vitamin D status on the relationship between lipid profile and high-sensitivity C-reactive protein (hs-CRP) in pregnant women.

Design

Serum 25-hydroxyvitamin D (25(OH)D), hs-CRP, and indicators of lipid profiles (total cholesterol, TC; triglyceride, TG; high-density lipoprotein cholesterol, HDL-C; low-density lipoprotein cholesterol, LDL-C), were measured in 2479 pregnant women during the second trimester. Potential confounding including maternal sociodemographic characteristics, perinatal health status, diet, and lifestyle was prospectively collected. Multiple regression models and cubic models were used to evaluate the associations.

Results

There was a significant non-linear relationship between lipid profile (TC, TG, HDL-C, LDL-C) and hs-CRP (P < 0.05). Increased serum 25(OH)D was significantly associated with decreasing TC, TG, HDL-C, LDL-C, and hs-CRP levels. Compared with medium levels of lipids group, pregnant women with higher levels of TC or TG have higher levels of hs-CRP, and pregnant women with lower levels of TC, HDL-C or LDL-C also have higher levels of hs-CRP in the vitamin D deficient group, and there was a significant correlation between low levels of TG and decreased hs-CRP (adjusted β for TG: -0.063, 95%CI: − 0.120,-0.007) in the non-vitamin D deficient group. Mediators that had appreciable shares of the associations between 25(OH)D and hs-CRP was TG (10.2% of the association; β = − 0.011; total indirect effect: 95% CI: − 0.019, − 0.002). The cubic model suggested that a steep increase in the adjusted regression coefficient of lipid with hs-CRP up to 50 nmol/L of 25(OH)D, and the highest adjusted regression coefficients were observed in pregnant women with 25(OH)D above 50 nmol/L.

Conclusion

Our findings suggest that high levels of vitamin D during pregnancy may improve lipid profile levels and inhibit elevated hs-CRP induced by high lipid metabolism.

Effect of dietary anthocyanins on biomarkers of glycemic control and glucose metabolism: A systematic review and meta-analysis of randomized clinical trials

Anthocyanins, as natural food colorants, are bioactive substances with several health advantages. In this research, the effects of dietary anthocyanins on biomarkers of glycemic control and glucose metabolism was evaluated through a meta-analysis. The results revealed a significant reduction in levels of fasting blood sugar (FBS; -2.70 mg/dl, 95% CI: -4.70 to -1.31; P < 0.001), 2-h postprandial glucose (2-h PPG; -11.1 mg/dl, 95% CI: -18.7 to -3.48; P = 0.004), glycated hemoglobin (HbA1c; -11.1 mg/dl, 95% CI: -18.7 to -3.48; P = 0.004), homeostasis model assessment of insulin resistance (HOMA-IR; -0.54, 95% CI: -0.94 to -0.14; P = 0.008), resistin (-1.23 µg/l, 95% CI: -2.40 to -0.05; P = 0.041), and plasminogen activator inhibitor-1 (PAI-1; -5.09 µg/l, 95% CI: -9.45 to -0.73; P = 0.022) following administration of anthocyanins, whilst changes in the levels of fasting insulin (0.33 mU/l, 95% CI: -0.18 to 0.85; P = 0.207) and C-peptide (-0.02 µg/l, 95 %CI: -0.20 to 0.16; P = 0.816) was not statistically significant. Consumption of anthocyanins for >8 weeks and at doses >300 mg/day significantly reduced levels of FBS, 2-h PPG, HbA1c, and HOMA-IR. Moreover, anthocyanins administration reduced the levels of FBS, 2-h PPG, HbA1c, and HOMA-IR in type 2 diabetic subjects and HOMA-IR in overweight/obese individuals. Overall, dietary anthocyanins can be used as an adjuvant therapy to improve biomarkers of glycemic control and glucose metabolism specially in diabetic subjects.

Aging Fits the Disease Criteria of the International Classification of Diseases

The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.

Effect of vitamin D supplementation on serum lipid profiles: a systematic review and meta-analysis

CONTEXT

Vitamin D deficiency is highly prevalent across the world. The existing evidence suggests vitamin D may have beneficial effects on serum lipid profiles and thus cardiovascular health.

OBJECTIVE

The objective of this systematic review and meta-analysis was to examine the effect of vitamin D supplementation on serum lipid profiles.

DATA SOURCE

Original randomized controlled trials (RCTs) examining the effect of vitamin D supplementation on serum lipid profiles and published before July 2018 were identified by searching online databases, including PubMed, Google Scholar, and ScienceDirect, using a combination of relevant keywords.

DATA EXTRACTION

Data on study characteristics, effect size, measure of variation, type of vitamin D supplementation, and duration of follow-up were extracted by the author.

DATA ANALYSIS

PRISMA guidelines for systematic reviews were followed. Random effects (DerSimonian and Laird [D-V)] models were used to pool standardized mean differences in total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides between the active and the placebo arms of RCT studies. Between-study heterogeneities were assessed using Cochrane Q and I2, and publication bias was assessed using Begg's test, Egger's test, and funnel plot.

RESULTS

A total of 41 RCTs comprising 3434 participants (n = 1699 in the vitamin D supplementation arm and n = 1735 in the placebo arm) were identified and included in the meta-analysis. Approximately 63.4% of study participants were women, with 14 studies conducted entirely among women. Approximately 24% of the trials had follow-up duration >6 months, whereas the remaining 76% had follow-up duration of <6 months. The standardized mean differences (SMDs) and 95% confidence intervals (CIs) for comparing the change from baseline to follow-up between the vitamin D supplementation arm and the placebo (control) arm were as follows: total cholesterol = -0.17 (-0.28 to -0.06); LDL cholesterol = -0.12 (-0.23 to -0.01); triglycerides = -0.12 (-0.25 to 0.01); and HDL cholesterol = -0.19 (-0.44 to 0.06). After removing a trial that was an outlier based on the magnitude of the effect size, the SMD for triglycerides was -0.15 (-0.24 to -0.06) and that for HDL cholesterol was -0.10 (-0.28 to 0.09). The improvements in total cholesterol and triglycerides were more pronounced in participants with baseline vitamin D deficiency.

CONCLUSIONS

Vitamin D supplementation appeared to have a beneficial effect on reducing serum total cholesterol, LDL cholesterol, and triglyceride levels but not HDL cholesterol levels. Vitamin D supplementation may be useful in hypercholesterolemia patients with vitamin D insufficiency who are at high risk of cardiovascular diseases.

No effect of vitamin D supplementation on metabolic parameters but on lipids in patients with type 2 diabetes and chronic kidney disease

Background/Aims: Trials on the effects of cholecalciferol supplementation in type 2 diabetes with chronic kidney disease patients were underexplored. Therefore, the aim of this study was to investigate the effects of two different doses of vitamin D supplementation on serum 25-hydroxyvitamin D [25(OH)D] concentrations and metabolic parameters in vitamin D-deficient Korean diabetes patients with chronic kidney disease. Methods: 92 patients completed this study: the placebo group (A, n = 33), the oral cholecalciferol 1,000 IU/day group (B, n = 34), or the single 200,000 IU injection group (C, n = 25, equivalent to 2,000 IU/day). 52% of the patients had less than 60 mL/min/1.73m² of glomerular filtration rates. Laboratory test and pulse wave velocity were performed before and after supplementation. Results: After 12 weeks, serum 25(OH)D concentrations of the patients who received vitamin D supplementation were significantly increased (A, -2.4 ± 1.2 ng/mL vs. B, 10.7 ± 1.2 ng/mL vs. C, 14.6 ± 1.7 ng/mL; p < 0.001). In addition, the lipid profiles in the vitamin D injection group (C) showed a significant decrease in triglyceride and a rise in HDL cholesterol. However, the other parameters showed no differences. Conclusions: Our data indicated that two different doses and routes of vitamin D administration significantly and safely increased serum 25(OH)D concentrations in vitamin D-deficient diabetes patients with comorbid chronic kidney disease. In the group that received the higher vitamin D dose, the lipid profiles showed significant improvement, but there were no beneficial effects on other metabolic parameters.

Effect of Vitamin D Supplementation on Lipid Profile in Vitamin D-Deficient Children with Type 1 Diabetes and Dyslipidemia

BACKGROUND

Vitamin D (VD) was suggested to have both direct and indirect effects on modifying lipid profile in patients with diabetes through its regulatory action that increases the activity of lipoprotein lipase in adiposity.

OBJECTIVES

To detect the relationship between serum 25-hydroxyvitamin D (25OHD) and lipid profiles in dyslipidemic T1D patients and study the effect of VD supplementation on lipid profiles of VD-deficient T1D patients.

METHODS

Fifty patients with T1D (for >2 years) and dyslipidemia were included. 25OHD was assessed and patients were divided accordingly into 2 groups: VD sufficiency (>30 ng/mL) and VD deficiency (VDD) or insufficiency (<29 ng/mL) who were allocated to VD3 supplementation for 4 months, then lipid profile was reevaluated in both groups.

RESULTS

Thirty patients had VDD, while 20 patients had VD sufficiency. There was no significant correlation between 25OHD and different study parameters (p > 0.05). A significant difference was found among both groups in the family history of coronary heart disease (p = 0.036) and free tetraiodothyronine 4 (p = 0.035). After 4 months of VD supplementation in VDD group, the mean difference (at 0 and 4 months) in low-density lipoproteins (LDL) and hemoglobin A1c (HbA1c) was statistically significant (p = 0.02 and 0.04 respectively) between both groups. The mean basal LDL was 126.91 mg/dL in VDD group that improved to 117.13 mg/dL after 4 months of VD therapy with a mean difference of -9.7 mg/dL compared to a mean difference of -2 mg/dL in VD sufficiency group.

CONCLUSIONS

VDD was highly prevalent in patients with T1D. There was no significant correlation between 25OHD levels and lipid profile in patients with T1D. VD supplementation for 4 months had a significant lowering effect on LDL and HbA1c.

Long-term vitamin D and high-dose n-3 fatty acids' supplementation improve markers of cardiometabolic risk in type 2 diabetic patients with CHD

This study was performed to evaluate the effects of vitamin D and n-3 fatty acids' co-supplementation on markers of cardiometabolic risk in diabetic patients with CHD. This randomised, double-blinded, placebo-controlled trial was conducted among sixty-one vitamin D-deficient diabetic patients with CHD. At baseline, the range of serum 25-hydroxyvitamin D levels in study participants was 6·3-19·9 ng/ml. Subjects were randomly assigned into two groups either taking 50 000 IU vitamin D supplements every 2 weeks plus 2× 1000 mg/d n-3 fatty acids from flaxseed oil (n 30) or placebo (n 31) for 6 months. Vitamin D and n-3 fatty acids' co-supplementation significantly reduced mean (P = 0·01) and maximum levels of left carotid intima-media thickness (CIMT) (P = 0·004), and mean (P = 0·02) and maximum levels of right CIMT (P = 0·003) compared with the placebo. In addition, co-supplementation led to a significant reduction in fasting plasma glucose (β -0·40 mmol/l; 95 % CI -0·77, -0·03; P = 0·03), insulin (β -1·66 μIU/ml; 95 % CI -2·43, -0·89; P < 0·001), insulin resistance (β -0·49; 95 % CI -0·72, -0·25; P < 0·001) and LDL-cholesterol (β -0·21 mmol/l; 95 % CI -0·41, -0·01; P = 0·04), and a significant increase in insulin sensitivity (β +0·008; 95 % CI 0·004, 0·01; P = 0·001) and HDL-cholesterol (β +0·09 mmol/l; 95 % CI 0·01, 0·17; P = 0·02) compared with the placebo. Additionally, high-sensitivity C-reactive protein (β -1·56 mg/l; 95 % CI -2·65, -0·48; P = 0·005) was reduced in the supplemented group compared with the placebo group. Overall, vitamin D and n-3 fatty acids' co-supplementation had beneficial effects on markers of cardiometabolic risk.

The Effects of Vitamin D Supplementation on Glycemic Control, Lipid Profiles and C-Reactive Protein Among Patients with Cardiovascular Disease: a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background:

Insulin resistance, dyslipidemia and chronic inflammation are important risk factors for cardiovascular diseases (CVD). Hence, vitamin D supplementation might be an appropriate approach to decrease the complications of CVD. This systematic review and meta-analysis aimed to determine the effects of vitamin D supplementation on glycemic control, lipid profiles, and C-reactive protein among patients with coronary artery disease.

Methods:

Two independent authors systematically searched online databases including EMBASE, Scopus, Pub- Med, Cochrane Library, and Web of Science until 20th September 2018. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochran’s Q test and I-square (I2) statistic. Data were pooled using a random-effects model and weighted mean difference (WMD) was considered as the overall effect size.

Results:

A total of eight trials (305 participants in the intervention group and 325 in placebo group) were included in the current meta-analysis. Pooling effect sizes from studies revealed a significant reduction in fasting glucose (WMD): -15.67; 95% CI: -29.32, -2.03), insulin concentrations (WMD: -3.53; 95% CI: -4.59, -2.46) and homeostatic model assessment of insulin resistance (WMD: -1.07; 95% CI: -1.49, -0.66), and significant increase in the quantitative insulin-sensitivity check index (WMD: 0.02; 95% CI: 0.01, 0.03) following the administration of vitamin D. In addition, pooled analysis revealed a significant increase in serum HDL-cholesterol concentrations following vitamin D therapy (WMD: 3.08; 95% CI: 1.42, 4.73). Additionally, vitamin D supplementation significantly reduced C-reactive protein (CRP) levels (WMD: -0.75; 95% CI: -1.28, -0.23).

Conclusion:

This meta-analysis demonstrated the beneficial effects of vitamin D supplementation on improving glycemic control, HDL-cholesterol and CRP levels among patients with CVD, though it did not affect triglycerides, total- and LDL-cholesterol levels.

Vitamin D ameliorates systolic but not diastolic blood pressure in patients with type 2 diabetes: Results from a meta-analysis of randomized controlled trials

Inconsistent findings have been reported regarding the effects of vitamin D on blood pressure in patients with type 2 diabetes (T2D). This study aimed to evaluate the subject through a meta-analysis. A computerized literature search on five databases was performed and randomized controlled trials (RCTs) published until March 2016 were identified. The eligibility criteria for articles to be selected were parallel-group RCTs in which consumption of a kind of vitamin D was compared with placebo in patients with T2D. Un-standardized mean difference and its corresponding 95 % confidence interval (CI) was calculated from the effect sizes by using random effects model. Studies comparing intervention group (received vitamin D) with control group (received placebo) were enrolled in meta-analysis. Meta-analysis on 26 studies with 1789 type 2 diabetic subjects showed that vitamin D significantly reduced systolic blood pressure (SBP; -0.97 mmHg, 95 % CI: -1.94, -0.001, P = 0.050), but not diastolic blood pressure (DBP; -0.10 mmHg, 95 % CI: -0.22, 0.02, P = 0.087). Subgroup analyses showed that administration of vitamin D in patients with baseline serum 25-hydroxy vitamin D < 50 nmol/l and baseline SBP < 140 mmHg significantly reduced SBP. Moreover, the patients who received vitamin D without Ca co-supplementation showed significant reduction in SBP. Vitamin D doses (≤ 2000 or > 2000 IU/day) and method of vitamin D application (Supplementation or food fortification) did not affect the blood pressure. This study demonstrated that vitamin D improved SBP in type 2 diabetic patients. Therefore, this vitamin can be considered as an adjuvant therapy in these patients.

Acute Effects of Single Doses of Bonito Fish Peptides and Vitamin D on Whole Blood Gene Expression Levels: A Randomized Controlled Trial

Fish contains high quality proteins and essential nutrients including 25-hydroxyvitamin D (25(OH)D). Fish peptide consumption can lower cardiovascular disease (CVD) risk factors, and studies have shown an association between 25(OH)D deficiency, CVD and CVD risk factors, such as diabetes. This study investigated acute effects of a single dose of cholecalciferol (VitD₃), bonito fish peptide hydrolysate (BPH), or a combination of both on CVD risk factors and whole blood gene expression levels. A randomized, crossover, placebo controlled trial was conducted in 22 adults. They ingested, in random order and at 7-day intervals, 1000 IU of VitD₃, 3 g of BPH, a combination of both, or a placebo. A 180 min oral glucose tolerance test was performed. Differences in whole-genome expression levels after versus before each supplementation were computed for 18 subjects. We observed that 16, 1 and 5 transcripts were differentially expressed post- vs. pre-ingestion for VitD₃, BPH or VitD₃ + BPH treatments, respectively. VitD₃-containing treatments affected the expression of the solute carrier family 25 member 20 (SLC25A20) gene involved in fatty acid oxidation, various transcription factors and genes related to glucose metabolism. These results suggest that VitD₃ rapidly modulates genes related to CVD risk factors in blood while BPH seems to moderately modulate gene expression levels.