Identification of a mechanism for increased cardiovascular risk among individuals with low vitamin D concentrations

Dietary supplementation with mushroom powder (Agaricus bisporus) on performance, carcass traits, meat quality, and bone biomechanical properties of quail (Coturnix coturnix japonica)

This study was performed to determine the effect of mushroom powder (MP) (Agaricus bisporus) supplementation on growing Japanese quail (Coturnix coturnix japonica). A total of 300 unsexed 1-day-old Japanese quails with similar body weights (8.38 ± 0.2 g) were randomly assigned to five treatment groups with six replications. Additions of 0, 0.25, 0.50, 0.75, or 1.00% of MP to the basal diet were used to develop the treatment groups. Quails were fed ad libitum for 42 days. At the end of the experiment, 12 quails from each experimental unit were euthanised to determine performance, carcass traits, meat quality, and bone biochemical properties. Results showed that all dietary MP did not negatively affect any performance parameters (P > 0.05), while by the third week of life, there was an increase (P < 0.05) in body weight and body weight gain in the quails of the 0.75% MP group compared to the control group. Nevertheless, these differences disappeared at the end of the trial (P > 0.05). No differences were observed (P > 0.05) for any of the studied carcass traits, except for the pancreas weight which decreased (P < 0.05) with the addition of high MP (1.00%). Regarding meat quality, all color parameters were affected on the fifth day of sampling (P < 0.05) but not on the first day (P > 0.05). It was detected that the breast of the quails in group 0.75% MP had the highest L* value and the lowest a* value. While the breast of the 1.00% MP group had the highest b value and the lowest pH value. Dietary MP enhanced oxidative stability, reducing malondialdehyde (MDA) value in the breast compared to the control at both sampling points (P < 0.01), being more noted on the fifth day of sampling. Bone biomechanical properties (in terms of shear force or shear stress) were improved (P < 0.01) with the dietary addition of MP at 0.75% compared to the control. It can be suggested that MP is a secure ingredient in animal feed without negatively affecting performance parameters, carcass traits, or meat quality. Therefore, including an interval of 0.50-0.75% of MP in the diet of growing quails could be a suitable strategy to improve certain parameters such as the meat's oxidative stability and the bone's biomechanical parameters. Moreover, the efficacy of MP on performance development would be greater during the first weeks of the quails' life due to their intestinal conditions at this stage.

Association between coronary artery vitamin D receptor expression and select systemic risks factors for coronary artery atherosclerosis

OBJECTIVE

The aim of this study is to analyze the association between coronary artery vitamin D receptor (VDR) expression and systemic coronary artery atherosclerosis (CAA) risk factors.

METHODS

Female cynomolgus monkeys (n = 39) consumed atherogenic diets containing the women's equivalent of 1000 IU/day of vitamin D₃. After 32 months consuming the diets, each monkey underwent surgical menopause. After 32 postmenopausal months, CAA and VDR expression were quantified in the left anterior descending coronary artery. Plasma 25OHD_3, lipid profiles and serum monocyte chemotactic protein-1 (MCP-1) were measured.

RESULTS

In postmenopausal monkeys receiving atherogenic diets, serum MCP-1 was significantly elevated compared with baseline (482.2 ± 174.2 pg/ml vs. 349.1 ± 163.2 pg/ml, respectively; p < 0.001; d = 0.79) and at the start of menopause (363.4 ± 117.2 pg/ml; p < 0.001; d = 0.80). Coronary VDR expression was inversely correlated with serum MCP-1 (p = 0.042). Additionally, the change of postmenopausal MCP-1 (from baseline to necropsy) was significantly reduced in the group with higher, compared to below the median, VDR expression (p = 0.038). The combination of plasma 25OHD₃ and total plasma cholesterol/high-density lipoprotein cholesterol was subsequently broken into low-risk, moderate-risk and high-risk groups; as the risk increased, the VDR quantity decreased (p = 0.04). CAA was not associated with various atherogenic diets.

CONCLUSION

Coronary artery VDR expression was inversely correlated with markers of CAA risk and inflammation, including MCP-1, suggesting that systemic and perhaps local inflammation in the artery may be associated with reduced arterial VDR expression.

Effects of Calcium and Vitamin D Co-supplementation on the Lipid Profile: A Systematic Review and Meta-analysis

PURPOSE

Calcium and vitamin D co-supplementation is common and widely used, but randomized, controlled trials (RCTs) have yielded inconclusive results concerning its impact on the serum lipid profile.

METHODS

A comprehensive literature search of Medline, Web of Science, Scopus, Embase, Cochrane Central Register of Controlled Trials, and clinical trial registry databases was conducted to identify placebo-controlled RCTs that were published through September 2020 and that evaluated the impact of calcium and vitamin D co-supplementation on total cholesterol (TC), triglycerides (TGs), low- and very-low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C). Standardized mean differences (SMDs) were pooled using random-effects meta-analysis models.

FINDINGS

Thirteen studies in a total of 2304 participants met the inclusion criteria. Calcium and vitamin D co-supplementation was associated with significant reductions in both TC (SMD, -0.81; 95% CI, -1.35 to -0.27; I² = 94.6%) and TGs (SMD, -0.50; 95% CI, -0.91 to -0.08; I² = 91.5%), and with a significant increase in HDL-C (SMD, 1.22; 95% CI, 0.60 to 1.83; I² = 95.4%). However, calcium and vitamin D co-supplementation were not found to be associated with significantly decreased low-density lipoprotein cholesterol (SMD, -0.39; 95% CI, -0.78 to 0.01; I² = 90.1%) or very-low-density lipoprotein cholesterol (SMD, -0.01; 95% CI, -0.70 to 0.69; I² = 82.3%).

IMPLICATIONS

The findings from the present systematic review and meta-analysis suggest that calcium and vitamin D co-supplementation has a beneficial effect on TC, TG, and HDL-C. Larger-scale, well-designed RCTs are needed to clarify the effect of calcium and vitamin D co-supplementation on all lipid-profile components.

Serum Lipid, Vitamin D Levels, and Obesity in Perimenopausal and Postmenopausal Women in Non-Manual Employment

BACKGROUND Increasing age, increased body mass index (BMI), and abnormal lipid profiles contribute to an increased risk of vitamin D deficiency. Women who have a perimenopausal and postmenopausal reduction in estrogen levels are a high-risk group for vitamin D deficiency. The aims of this study were to compare the serum vitamin D levels, lipid profile, and BMI between perimenopausal and postmenopausal women in non-manual employment, and to determine whether there were any interdependent factors. MATERIAL AND METHODS Three hundred women in non-manual employment, aged between 44-66 years, were divided into three groups: early perimenopausal; late perimenopausal; and postmenopausal. Laboratory tests included measurement of serum lipid profiles and vitamin D levels, the BMI, waist-hip ratio (WHR) and body fat were measured. Statistical analysis included F-test analysis of variance and the least significance difference (LSD) test was used for multiple comparisons. RESULTS For the 300 women who were in non-manual employment, and in the early and late perimenopausal and postmenopausal periods, serum vitamin D levels were reduced (mean 16.8±8.7 ng/mL); 29% of women had abdominal obesity; 41% had excessive body fat accumulation; and 56% had an increased body mass index (BMI) (>25 kg/m²) with raised total cholesterol, low-density lipoprotein (LDL) cholesterol, LDL/high-density lipoprotein (HDL), and total cholesterol/HDL ratios (p<0.05). CONCLUSIONS The findings of this study showed that in perimenopausal and postmenopausal women in non-manual employment, serum vitamin D levels were associated with serum lipid profile and degrees of obesity.

Consumption of vitamin D2 enhanced mushrooms is associated with improved bone health

Mushrooms are the best nonanimal food source of vitamin D2. Pulsed irradiation can enhance vitamin D2 in mushrooms quickly. We investigated the effect of supplementing high vitamin D2Pleurotus ferulae mushrooms in a mouse model of osteoporosis. Thirty-two female C57BL/6JNarl mice were divided into four groups including sham, ovariectomized (OVX), OVX+nonpulsed mushroom (NPM) and OVX+pulsed mushroom (PM). After 23 weeks of treatment, serum samples were analyzed for osteoblast and osteoclast indicators, as well as metabolites using NMR spectroscopy. To examine bone density, femurs were analyzed using micro-computed tomography. The NPM and PM treatment mice showed increased bone density in comparison with OVX mice. In addition, the PM mice showed higher osteoblast and lower osteoclast indicators in comparison with OVX mice. Serum metabolomics analysis indicated several metabolites that were different in PM mice, some of which could be correlated with bone health. Taken together, these results suggest that pulsed irradiated mushrooms are able to increase bone density in osteoporotic mice possibly through enhanced bone metabolism. Further studies in humans are needed to show their efficacy in preventing osteoporosis.

Calcium/vitamin D supplementation, serum 25-hydroxyvitamin D concentrations, and cholesterol profiles in the Women's Health Initiative calcium/vitamin D randomized trial

OBJECTIVE

The objective of this study was to evaluate whether increased serum 25-hydroxyvitamin D3 (25OHD3) concentrations, in response to calcium/vitamin D (CaD) supplementation, are associated with improved lipids in postmenopausal women.

METHODS

The parent trial was a double-blind, randomized, placebo-controlled, parallel-group trial designed to test the effects of CaD supplementation (1,000 mg of elemental calcium + 400 IU of vitamin D3 daily) versus placebo in postmenopausal women. Women from the general community, including multiple sites in the United States, were enrolled between 1993 and 1998. This cohort included 300 white, 200 African-American, and 100 Hispanic participants who were randomly selected from the Women's Health Initiative CaD trial. Serum 25OHD3 and lipid (fasting plasma triglycerides [TG], high-density lipoprotein cholesterol [HDL-C], and calculated low-density lipoprotein cholesterol [LDL-C]) levels were assessed before and after CaD randomization.

RESULTS

There was a 38% increase in mean serum 25OHD3 concentrations after 2 years (95% CI, 1.29-1.47, P < 0.001) for women randomized to CaD (24.3 ng/mL postrandomization mean) compared with placebo (18.2 ng/mL). Women randomized to CaD had a 4.46-mg/dL mean decrease in LDL-C (P = 0.03). Higher concentrations of 25OHD3 were associated with higher HDL-C levels (P = 0.003), along with lower LDL-C and TG levels (P = 0.02 and P < 0.001, respectively).

CONCLUSIONS

Supplemental CaD significantly increases 25OHD3 concentrations and decreases LDL-C. Women with higher 25OHD3 concentrations have more favorable lipid profiles, including increased HDL-C, lower LDL-C, and lower TG. These results support the hypothesis that higher concentrations of 25OHD3, in response to CaD supplementation, are associated with improved LDL-C.

Association between vitamin D status and risk of metabolic syndrome among Korean postmenopausal women

This study aimed to investigate the association between serum levels of 25-hydroxyvitamin D [25(OH)D] and metabolic syndrome along with its associated risk factors in Korean postmenopausal women. This study was performed using data from the KNHANES 2008–2010 study and included 4,364 postmenopausal Korean women. Clinical and other objective characteristics, seasonality, and presence of metabolic syndrome with its five components were evaluated and correlated with the serum levels of 25(OH)D. Although no statistically significant associations were observed between the levels of serum 25(OH)D and the prevalence of metabolic syndrome, the adjusted OR for elevated blood pressure, elevated triglycerides (TGs), and reduced high-density lipoprotein cholesterol (HDL-C) showed tendency to decrease sequentially as tertiles of serum 25(OH)D levels increased (p for trends  = 0.066, 0.043, and 0.010, respectively). Women in the highest tertile of serum 25(OH)D showed a significant decrease in the prevalence of elevated blood pressure, elevated TGs, and reduced HDL-C as compared with those in the lowest tertile of serum 25(OH)D (p = 0.020, 0.014, and 0.002, respectively). Based on these results, we consider that adequate serum levels of 25(OH)D in Korean postmenopausal women may not entirely indicate a lower risk of developing metabolic syndrome. However, adequate serum levels of 25(OH)D are significantly associated with a decrease in elevated blood pressure, elevated TGs, and reduced HDL-C levels in postmenopausal women.

Vitamin D and cardiovascular disease: an appraisal of the evidence

BACKGROUND

Supplementation with vitamin D has received attention as a potential cardioprotective strategy. Biologically plausible mechanisms have been proposed to link vitamin D to coronary heart disease (CHD) prevention, and observational studies suggest an inverse association between serum 25-hydroxyvitamin D (25OHD) concentrations and CHD. Few randomized clinical trials of vitamin D supplementation and CHD have been conducted, however, and no trial with CHD as the primary prespecified outcome has been completed.

CONTENT

A search was conducted in PubMed to find prospective studies of the use of vitamin D supplementation and its relationship to cardiovascular risk factors (RFs) and/or cardiovascular disease (CVD). The exact search query was: ((vitamin D supplement*[Title/Abstract]) AND cardiovascular [Title/Abstract]) AND prospective [Title/Abstract]. This query yielded 42 results. "Randomized Controlled Trial" (article type) was used as a filter in a subsequent query with the same search terms. We review the evidence that vitamin D supplementation modifies coronary RFs, such as blood pressure, lipids, glucose tolerance, and/or affects the development of clinical CHD events. We address potential sources of confounding in observational epidemiologic studies of the relationship between serum 25OHD and CHD. We also address laboratory assay issues relevant to the reliable measurement of 25OHD.

SUMMARY

Most vitamin D supplementation trials have not demonstrated improvement in CVD, but they have tested relatively low vitamin D doses. Thus, the evidence remains inconclusive, highlighting the need for rigorous randomized trials of higher vitamin D doses with cardiovascular events as prespecified outcomes. While we await the results of ongoing trials, the recommended dietary allowances from the Institute of Medicine remain the best guidepost for nutritional requirements.

The association between plasma 25-hydroxyvitamin D3 concentrations, C-reactive protein levels, and coronary artery atherosclerosis in postmenopausal monkeys

OBJECTIVE

The aim of this study was to identify the potential relationships between plasma 25-hydroxyvitamin D(3) (25OHD(3)), C-reactive protein (CRP), coronary artery atherosclerosis (CAA), and coronary artery remodeling in monkeys consuming atherogenic diets.

METHODS

Female cynomolgus monkeys (n = 74) were fed a casein-lactalbumin (C/L)-based, moderately atherogenic diet for 12 months. They then consumed either a soy-based (n = 35) or C/L-based (n = 39) diet for 32 months. CRP concentrations were then determined, and monkeys underwent surgical menopause. Each diet group was then rerandomized to receive soy (n = 36) or C/L (n = 38). After 32 postmenopausal months, 25OHD(3), CRP, CAA, and coronary artery remodeling were determined. All monkeys received a woman's equivalent of 1,000 IU/day of vitamin D(3) and 1,200 mg/day of calcium throughout the study.

RESULTS

The premenopausal and postmenopausal dietary protein sources had no effect on postmenopausal 25OHD(3) concentrations (P = 0.6). Across treatment groups, there was a statistically significant inverse relationship between 25OHD(3) concentrations and CRP at necropsy (r = -0.35, P = 0.003). A significant inverse correlation between 25OHD(3) concentration and the change in CRP from premenopause to postmenopause was observed (r = -0.32, P = 0.007). The significant associations identified between plasma 25OHD(3) and CRP remained after controlling for postmenopausal diet. Those monkeys with a greater increase in CRP also had significantly more CAA and less ability to maintain normal lumens by remodeling.

CONCLUSIONS

Higher plasma concentrations of 25OHD(3) were associated with lower CRP. Lower CRP was associated with less coronary atherosclerosis and improved coronary artery remodeling. These findings suggest that 25OHD(3) concentrations are associated with an anti-inflammatory state and may support an association between oral vitamin D3 and cardioprotection.

The quantification of vitamin D receptors in coronary arteries and their association with atherosclerosis

OBJECTIVE

The activated vitamin D receptor (VDR) may have an important role in vascular health. The objective of this study was to determine whether there is an association between the expression of VDRs in coronary arteries and the extent of diet-induced atherosclerosis.

METHODS

Utilizing a cohort of 39 postmenopausal female cynomolgus monkeys with varying stages of atherosclerosis, histologic sections of the left anterior descending artery (LAD) were analyzed for plaque cross-sectional area, plaque thickness, and VDR quantity using immunohistochemical H-score analysis. The quantities of VDRs were analyzed as a continuous variable and were divided at the median intimal H-score into high vs. low groupings.

RESULTS

In the LAD, a significant negative correlation was observed between the quantity of VDR and plaque size (both cross-sectional area [p<0.001] and plaque thickness [p<0.001]). Monkeys in the low VDR group had a significantly greater cross-sectional plaque area (1.2mm(2)) and greater plaque thickness (0.3mm) than those in the high VDR group (0.4mm(2), p=0.005; 0.1mm, p=0.003, respectively).

CONCLUSIONS

Lower concentrations of VDRs in a main coronary artery were associated with greater atherosclerotic plaque size in postmenopausal female monkeys. Given that coronary artery atherosclerosis is a major cause of coronary heart disease in postmenopausal women, further research to ascertain the relationship between VDRs and atherosclerosis is warranted.

Coronary artery vitamin D receptor expression and plasma concentrations of 25-hydroxyvitamin D: their association with atherosclerosis

OBJECTIVE

The aim of this study was to analyze coronary artery vitamin D receptor (VDR) expression, the plasma concentrations of 25-hydroxyvitamin D3 (25OHD3), and their relationship with coronary artery atherosclerosis.

METHODS

Premenopausal cynomolgus monkeys were fed atherogenic diets containing the equivalent of 1,000 IU/day of vitamin D3. Protein was derived from casein-lactalbumin (C/L, n = 10), soy protein isolate (soy, n = 10), or a combination (n = 19). After 32 months of consuming the diets, each monkey underwent surgical menopause. After 32 postmenopausal months, coronary atherosclerosis was measured in the left circumflex (LCX) artery and left anterior descending (LAD) artery. VDR expression was determined for the LAD, and 25OHD3 concentrations were assessed.

RESULTS

Both the cross-sectional area of atherosclerotic plaques (in square millimeters) and plaque thickness (in millimeters) in the LCX as well as the LAD arteries were analyzed in these monkeys. Those with higher plasma vitamin D3 concentrations and higher VDR were compared with those with higher plasma 25OHD3 concentrations and lower VDR. Significantly smaller plaque sizes were noted with higher plasma 25OHD3 concentrations and higher VDR. For the LCX artery, there was also a significantly lower plaque size (both plaque thickness and cross-sectional area) in those with higher quantities of VDR and lower 25OHD3 concentrations versus those with lower quantities of VDR and higher plasma concentrations of 25OHD3 (P = 0.009 and P = 0.040, respectively).

CONCLUSIONS

Cynomolgus monkeys with higher quantities of VDR have significantly less atherosclerosis than do those with lower quantities of VDR and higher plasma 25OHD3 concentrations. If these findings translate to human beings, it might explain why some individuals with higher plasma concentrations of 25OHD3 have more coronary artery atherosclerosis.

25(OH)D3 and cardiovascular risk factors in female nonhuman primates

OBJECTIVE

To determine if interindividual differences in plasma concentrations of 25-hydroxyvitamin D(3) (25(OH)D(3)) have pathophysiologic significance, we evaluated a cohort of female monkeys, seeking to identify associations with clinically relevant cardiovascular risk factors, including age, abdominal obesity (waist circumference), and high-density lipoprotein cholesterol (HDL-C).

METHODS

One hundred fifty-five female vervet monkeys (Chlorocebus aethiops sabaeus) aged 3-25 years consumed a typical western diet for 7-8 weeks that provided a woman's equivalent of approximately 1000 IU/day of vitamin D(3). Measurements of vitamin D(3) and HDL-C concentrations, as well as waist circumference, were obtained.

RESULTS

Among young monkeys (aged 3-5 years), compared to older monkeys (aged 16-25 years), the mean plasma 25(OH)D(3) concentrations were 82.3±3.2 ng/mL and 58.6±2.9 ng/mL (p<0.0001), respectively. Plasma 25(OH)D(3) concentrations had a range of 19.6-142.0 ng/mL (mean±standard error [SE] 66.4±1.7 ng/mL). 25(OH)D(3) concentrations were inversely associated with age (p<0.0001) and waist circumference (p=0.016) and were positively correlated with HDL-C (p=0.01). However, when statistically controlling for age, none of these relationships remained significant.

CONCLUSIONS

Higher plasma concentrations of 25(OH)D(3) were associated with more favorable cardiovascular risk factors, with inverse associations observed between 25(OH)D(3) and abdominal obesity, HDL-C, and age. These associations were no longer significant when controlling for age.