Vitamin D and bone health in childhood and adolescence

Effects of vitamin D3 supplementation on strength of lower and upper extremities in athletes: an updated systematic review and meta-analysis of randomized controlled trials

Background

Coaches and athletes are increasingly interested in understanding athletes' serum vitamin D levels, their impact on strength, physical performance, and athletic outcomes. Previous meta-analyses were reported with limited sample size and no significant overall effect was found. Hence, it is crucial to conduct a thorough and up-to-date systematic examination and meta-analysis to elucidate the potential advantages of supplementing with vitamin D3 in enhancing muscle strength for athletes.

Methods

We performed a thorough investigation, spanning three databases (PubMed, EBSCO, and Cochrane Library), seeking randomized controlled trials (RCTs) in all languages. These trials delved into the influence of vitamin D3 supplementation on the changes of pre- and post-intervention muscle strength in healthy athletes. Our systematic examination and meta-analysis took into account serum 25(OH)D levels exceeding 30 ng/mL as a marker of adequacy.

Results

Ten RCTs, comprising 354 athletes (185 in the vitamin D3 group and 169 in the placebo group), fulfilled the inclusion criteria. During the study, 36 athletes were lost to follow-up, leaving 318 athletes (166 in the vitamin D3 group and 152 in the placebo group) with documented complete results. In comparison with the placebo group, there is a significant increase between the changes of pre- and post-intervention serum 25(OH)D levels among athletes following a period of vitamin D3 supplementation (MD 14.76, 95% CI: 8.74 to 20.77, p < 0.0001). Overall effect of four strength measurements including handgrip, one repetition maximum Bench Press (1-RM BP), vertical jump, and quadriceps contraction was not significantly improved (SMD 0.18, 95% CI: -0.02 to 0.37, p = 0.08), but there was a significant increase in quadriceps contraction (SMD 0.57, 95% CI: 0.04 to 1.11, p = 0.04).

Conclusion

This updated meta-analysis indicates the potential benefits of vitamin D supplementation for enhancing muscle strength in athletes when analyzing its quantitatively synthesized effects. With limited available studies for the quantitative synthesis, it cannot warrant significant overall enhancements in muscle strength when athletes attain adequate serum 25(OH)D levels through supplementation.

Egg consumption and bone mass density among the elderly: A scoping review

Eggs offer a range of essential nutrients that could support skeletal health as individuals age. Maintaining bone density is crucial for reducing the risk of fractures and improving overall mobility and quality of life in later years. Understanding the potential benefits of habitual egg consumption on bone mass density among older people is essential, given that the natural decline in bone mass density occurs with age. This area of research has not garnered sufficient attention basically because of the mixed reactions and conflicting reports about the safety of egg consumption especially among the older adults. This scoping review aims to systematically examine the existing literature to map the evidence regarding the association between habitual egg consumption and bone mass density in older adults' individuals. The scoping review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines to ensure methodological rigor and transparency. Five electronic databases were searched for published pieces of literature. While high egg intake has been linked to increased mortality and dyslipidemia, eggs contain compounds like Ovo transferrin and carotenoids that may benefit bone health. As aging increases vulnerability to bone fragility and fractures, it's crucial to provide comprehensive dietary recommendations. The complex relationship between egg consumption, cholesterol, and health highlights the need for nuanced assessment. Overall, eggs present a potentially valuable dietary component for promoting bone health in aging populations. Limited research on the link between egg consumption and bone mass density in older adults highlights the need for further investigation. Concerns about cholesterol have overshadowed potential benefits. Given aging populations and bone health challenges, exploring eggs' role in preventing falls and fractures is essential for a proactive approach to older adults' well-being.

Association of serum 25-hydroxyvitamin D with bone health measured by calcaneal quantitative ultrasound: a large cross-sectional analysis in children and adolescents

Background: Vitamin D plays a crucial role in bone health; however, findings in children and adolescents remain inconsistent, and few studies have examined its impact on bone health measured by quantitative ultrasound (QUS). This study aims at assessing the relationship between serum vitamin D levels and bone health, as evaluated by QUS, across varying pubertal stages and genders. Methods: A baseline cross-sectional survey of an ongoing cohort study included 4682 children and adolescents aged 6 to 18 years from Shenzhen, China. Serum levels of 25-hydroxyvitamin D (25(OH)D), which is the sum of 25(OH)D2 and 25(OH)D3, were quantified using liquid chromatography-mass spectrometry. Bone health was measured through calcaneal QUS, utilizing the speed of sound (SOS) in the heel as a principal measure-a higher SOS indicating a denser bone structure. Generalized linear models were used to evaluate the association of serum 25(OH)D, 25(OH)D2, and 25(OH)D3 levels with the SOS. Results: Forty-one point-one percent of this population was vitamin D deficient (serum 25(OH)D < 20 ng ml-1), with only 11.1% being sufficient. In the fully adjusted model, we observed a significant positive association between increased serum 25(OH)D quartiles and SOS. Compared with the participants in the lowest quartiles of serum 25(OH)D, those in successive quartiles of 25(OH)D were 3.54 (95% CI: 0.81, 6.28) m s-1, 5.74 (95% CI: 2.87, 8.61) m s-1, and 8.83 (95% CI: 5.83, 11.84) m s-1, respectively (P for trend < 0.0001). The correlations observed for serum 25(OH)D2 and 25(OH)D3 with SOS were similar to those of serum 25(OH)D. Importantly, this association was primarily observed in post-pubertal children and adolescents but was absent in pre- and mid-pubertal participants (P for interaction = 0.0004). Conclusion: Elevated serum 25(OH)D levels were associated with better bone health, as measured through calcaneal QUS, in children and adolescents, particularly among those who had reached the post-pubertal stage. These findings highlight the crucial importance of maintaining sufficient vitamin D levels to support optimal bone health in this demographic.

Early-life famine exposure, adulthood obesity patterns, and risk of low-energy fracture

Malnutrition in early life increases the risk of osteoporosis, but the association of early-life undernutrition combined with adulthood obesity patterns with low-energy fracture remains unknown. This study included 5323 community-dwelling subjects aged ⩾40 years from China. Early-life famine exposure was identified based on the participants' birth dates. General obesity was assessed using the body mass index (BMI), and abdominal obesity was evaluated with the waist-to-hip ratio (WHR). Low-energy fracture was defined as fracture occurring after the age of ⩾40 typically caused by falls from standing height or lower. Compared to the nonexposed group, the group with fetal, childhood, and adolescence famine exposure was associated with an increased risk of fracture in women with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.55 (1.57-8.05), 3.90 (1.57-9.71), and 3.53 (1.05-11.88), respectively, but not in men. Significant interactions were observed between fetal famine exposure and general obesity with fracture among women (P for interaction = 0.0008). Furthermore, compared with the groups with normal BMI and WHR, the group of women who underwent fetal famine exposure and had both general and abdominal obesity had the highest risk of fracture (OR, 95% CI: 3.32, 1.17-9.40). These results indicate that early-life famine exposure interacts with adulthood general obesity and significantly increases the risk of low-energy fracture later in life in women.

Food sources of fiber and micronutrients of concern among infants and young children in Lebanon: a national cross-sectional study

BACKGROUND

Intakes of fiber, iron, zinc, calcium, vitamin D, vitamin A, and folate were shown to be low in a substantial proportion of infants and children in Lebanon. The study aims to identify the top food sources of fiber, iron, zinc, calcium, vitamin D, vitamin A, and folate amongst infants and young children in Lebanon and to evaluate the evolution of food sources of these nutrients from the beginning of the complementary feeding journey up until the age of 47.9 months.

METHODS

A national cross-sectional survey was conducted in 2012 as part of the "Early Life Nutrition and Health in Lebanon" project using stratified cluster sampling. Dietary intakes for infants and young children aged 6-47.9 months (n = 763) were assessed using 24- Hour Dietary Recall. Food items were categorized into food groups and the percent contribution of each food group to nutrient intakes was determined to identify the top food sources of fiber and selected micronutrients for three age groups: 6-11.9 m (infants), 12-23.9 m (toddlers), and 24-47.9 m (preschoolers).

RESULTS

The top food source of fiber was vegetables among children aged 6-47.9 months. Among infants and toddlers, infant/young child formula was the main contributor to iron, zinc, calcium, vitamin D, vitamin A, and folate intakes. Baby cereals also contributed to around 14% of iron intakes among infants. Among preschoolers, meat and fish contributed to 13% of iron intakes and 29% of zinc intakes, while cow's milk was the major contributor of calcium (41%), vitamin D (81%) and vitamin A (25%) intakes. Sweetened beverages and sweet bakery were also ranked among the major food sources contributing to substantial intakes of key nutrients, including fiber, iron, zinc, calcium, vitamin A, and folate among infants, toddlers, and preschoolers.

CONCLUSIONS

In addition to milk sources, vegetables, beans and legumes, breads, meats, and rice and pasta, sweet bakery and sweetened beverages have contributed to intakes of key nutrients from early ages. This calls for implementing initiatives and designing approaches to support nutrition education and improve nutrient intakes in infancy and early childhood.

Vitamin D supplementation for improving bone density in vitamin D-deficient children and adolescents: systematic review and individual participant data meta-analysis of randomized controlled trials

BACKGROUND

Vitamin D supplements are widely used for improving bone health in children and adolescents, but their effects in vitamin D-deficient children are unclear.

OBJECTIVES

This study aimed to examine whether the effect of vitamin D supplementation on bone mineral density (BMD) in children and adolescents differs by baseline vitamin D status and estimate the effect in vitamin D-deficient individuals.

METHODS

This is a systematic review and individual participant data (IPD) meta-analysis. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, MBASE, CINAHL, AMED, and ISI Web of Science (until May 27, 2020) for randomized controlled trials (RCTs) of vitamin D supplementation reporting bone density outcomes after ≥6 mo in healthy individuals aged 1-19 y. We used two-stage IPD meta-analysis to determine treatment effects on total body bone mineral content and BMD at the hip, femoral neck, lumbar spine, and proximal and distal forearm after 1 y; examine whether effects varied by baseline serum 25-hydroxyvitamin D [25(OH)D] concentration, and estimate treatment effects for each 25(OH)D subgroup.

RESULTS

Eleven RCTs were included. Nine comprising 1439 participants provided IPD (86% females, mean baseline 25(OH)D = 36.3 nmol/L). Vitamin D supplementation had a small overall effect on total hip areal BMD (weighted mean difference = 6.8; 95% confidence interval: 0.7, 12.9 mg/cm2; I2 = 7.2%), but no effects on other outcomes. There was no clear evidence of linear or nonlinear interactions between baseline 25(OH)D and treatment; effects were similar in baseline 25(OH)D subgroups (cutoff of 35 or 50 nmol/L). The evidence was of high certainty.

CONCLUSIONS

Clinically important benefits for bone density from 1-y vitamin D supplementation in healthy children and adolescents, regardless of baseline vitamin D status, are unlikely. However, our findings are mostly generalizable to White postpubertal girls and do not apply to those with baseline 25(OH)D outside the studied range or with symptomatic vitamin D deficiency (e.g., rickets). This study was preregistered at PROSPERO as CRD42017068772. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42017068772.

Association between Vitamin D Levels, Puberty Timing, and Age at Menarche

Pubertal development represents the process of physical maturation where an adolescent reaches sexual maturity and attains reproductive function. The effects of vitamin D are mainly mediated by the vitamin D receptor (VDR), which is expressed in almost all body cells, including the ovary and human pituitary gland and animal hypothalamus. Thus, vitamin D has gained great interest as pathogenic factor of pubertal disorders and fertility. This narrative review aimed to provide a broad overview of the available literature regarding the association between vitamin D levels, puberty timing, and age at menarche. A review of the data on the involvement of micronutrient deficiency, as a modifiable cause of pubertal disorders, is important for the prediction and prevention of deficiencies as well as for fertility protection and should be considered a public health priority. Reported data support that vitamin D is a regulator of neuroendocrine and ovarian physiology and, more in detail, a deficiency of vitamin D is involved in altered pubertal timing. Considering the long-term consequences of early pubertal development and early menarche, the detection of modifiable causes is crucial in preventive strategies. Future studies in humans and with an increased scale are needed to elucidate the vitamin D role in sexual maturation and puberty development.

Pediatric Fractures: Does Vitamin D Play a Role?

BACKGROUND

Vitamin D (25-OHD) deficiency and insufficiency are reported in about half of all children. The literature on low 25-OHD and pediatric fracture risk presents inconsistent results. This study evaluates the association between pediatric fractures and 25-OHD, parathyroid hormone (PTH), and calcium.

METHODS

This is a prospective case-control study in 2 urban pediatric emergency departments (2014-2017). Patients aged 1 to 17 requiring intravenous access were enrolled. Demographics, nutrition, and activity information were recorded and levels of 25-OHD, calcium, and PTH were measured.

RESULTS

Two hundred forty-five subjects were enrolled: 123 fractures and 122 controls. Overall, the mean 25-OHD level was 23 ng/mL±8.5: 52 (21%) of patients were 25-OHD sufficient; 193 (79%) were not. Ninety-six percent of patients with lower extremity fractures had low 25-OHD versus 77% of patients with upper extremity fractures (P=0.024). The fracture cohort was younger (P=0.002), included more males (P=0.020), and spent more time playing outdoor sports (P=0.011) than the control cohort. The 25-OHD level (fracture 22.8 ng/mL±7.6 vs. nonfracture 23.5 ng/mL±9.3, P=0.494) and median calcium level (fracture 9.8 mg/dL vs. nonfracture 10.0 mg/dL, P=0.054) were similar between cohorts. The median PTH level was higher in the fracture than the control cohort (33 vs. 24.5 pg/mL; P<0.0005); PTH was elevated to hyperparathyroidism (>65 pg/mL) in 13% of fractures and 2% of controls (P=0.006). Matched subgroup analysis of 81 fracture patients and 81 controls by age, gender, and race showed that PTH was the only variable independently associated with increased odds of fracture (odds ratio=1.10, 95% CI, 1.01-1.19, P=0.021) in a model adjusted for vitamin D sufficiency and time spent playing outdoor sports.

CONCLUSIONS

Low 25-OHD is common in children with fractures but we found no difference in 25-OHD levels between fracture and nonfracture cohorts. This research can impact evidence-based guidelines on vitamin D level screening and/or supplementation after fracture.

LEVEL OF EVIDENCE

Diagnostic level IV-case-control study.

Relationship Between Hypovitaminosis D and Fractures Among Adolescents With Overweight or Obesity

Adolescents with overweight/obesity are at risk for vitamin D insufficiency and deficiency. Both overweight/obesity and vitamin D insufficiency/deficiency may predispose to fractures. We enrolled 103 participants (53.3% females, 15.9 ± 2.2 years) in a retrospective case-control study to determine whether an association exists between fractures and a low 25-hydroxyvitamin D (25[OH]D) among adolescents whose body mass index (BMI) ≥ 85 percentile. Cases (n = 28) sustaining a low/medium impact fracture were matched to controls (n = 75) without a fracture history. A conditional-logistic regression analysis addressing the common vitamin D insufficiency/deficiency cutoffs was used. Overweight, obesity, and significant obesity rates were 10.7%, 53.4%, and 35.9%, respectively. Mean (±SD) 25(OH)D was 16.5 ± 6.4 ng/mL. In all, 25(OH)D insufficiency rates (level <20 ng/mL) were 70.5%. Matched cases and controls had similar 25(OH)D insufficiency/deficiency rates (P > .05). Controlling for race and seasonality showed no association between fractures and 25(OH)D insufficiency/deficiency (P > .05). These data suggest that fractures are not associated with low 25(OH)D levels among adolescents whose BMI ≥ 85th percentile.

The Combined Relationship of Vitamin D and Weight-Bearing Sports Participation on Areal Bone Density and Geometry Among Adolescents: ABCD - Growth Study

Osteoporosis is a public health problem, which negatively impacts society and national health services worldwide. Altered mineralization of the skeleton can be caused by persistent vitamin D deficiency. However, the combined impact of both on bone health is still under investigation. In fact, although there is compelling evidence in the literature about the positive effect of weight-bearing sports participation on bone mineral density, its impact on bone geometry gains more attention in pediatric population. The sports modalities that we evaluated were artistic gymnastics and track and field. Nonsports group was composed of 43 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Vitamin D concentration was assessed by blood analysis. In the crude comparison of bone outcomes, the sport group presented higher aBMD only in the trochanter (p-value = 0.040). Considering the combination of the engagement in sports and vitamin D, adolescents in the sports group presented significantly higher values of aBMD in lower limbs, whole body, trochanter, shaft, and femur whole body (p-value = 0.024, 0.035, 0.001, 0.019 and 0.003 respectly). In contrast, only the sport group with high vitamin D presented a higher CSA (p-value = 0.015) and femur neck aBMD compared to the non-sport/low vitamin D group. Only adolescents with a combination of sports participation and higher serum concentrations of vitamin D presented better bone geometry, denoting the relevance of the combination of both factors to bone health.

The Crosstalk between Vitamin D and Pediatric Digestive Disorders

Vitamin D is a cyclopentane polyhydrophenanthrene compound involved mainly in bone health and calcium metabolism but also autophagy, modulation of the gut microbiota, cell proliferation, immune functions and intestinal barrier integrity. The sources of vitamin D include sunlight, diet and vitamin D supplements. Vitamin D3, the most effective vitamin D isoform is produced in the human epidermis as a result of sunlight exposure. Vitamin D undergoes two hydroxylation reactions in the liver and kidney to reach its active form, 1,25-dihydroxyvitamin D. Recent studies highlighted a complex spectrum of roles regarding the wellbeing of the gastrointestinal tract. Based on its antimicrobial effect, it was recently indicated that vitamin D supplementation in addition to standard eradication therapy might enhance H. pylori eradication rates. Moreover, it was suggested that low levels of vitamin D might also be involved in the acquisition of H. pylori infection. In terms of celiac disease, the negative effects of vitamin D deficiency might begin even during intrauterine life in the setting of maternal deficiency. Moreover, vitamin D is strongly related to the integrity of the gut barrier, which represents the core of the pathophysiology of celiac disease onset, in addition to being correlated with the histological findings of disease severity. The relationship between vitamin D and cystic fibrosis is supported by the involvement of this micronutrient in preserving lung function by clearing airway inflammation and preventing pathogen airway colonization. Moreover, this micronutrient might exert anticatabolic effects in CF patients. Inflammatory bowel disease patients also experience major benefits if they have a sufficient level of circulating vitamin D, proving its involvement in both induction and remission in these patients. The findings regarding the relationship between vitamin D, food allergies, diarrhea and constipation remain controversial, but vitamin D levels should be monitored in these patients in order to avoid hypo- and hypervitaminosis. Further studies are required to fill the remaining gaps in term of the complex impact of vitamin D on gastrointestinal homeostasis.

Fat-soluble vitamins: updated review of their role and orchestration in human nutrition throughout life cycle with sex differences

Age and Gender are vital determinants for the micronutrient demands of normal indviduals. Among these micronutrients are vitamins that are required in small amounts for optimum metabolism, homeostasis, and a healthy lifestyle, acting as coenzymes in several biochemical reactions. The majority of previous studies have examined such issues that relates to a specific vitamin or life stage, with the majority merely reporting the effect of either excess or deficiency. Vitamins are classified into water-soluble and fat-soluble components. The fat-soluble vitamins include vitamins (A, D, E, and K). Fat-soluble vitamins were found to have an indisputable role in an array of physiological processes such as immune regulation, vision, bone and mental health. Nonetheless, the fat-soluble vitamins are now considered a prophylactic measurement for a multitude of diseases such as autism, rickets disease, gestational diabetes, and asthma. Herein, in this review, a deep insight into the orchestration of the four different fat-soluble vitamins requirements is presented for the first time across the human life cycle beginning from fertility, pregnancy, adulthood, and senility with an extensive assessment ofthe interactions among them and their underlying mechanistic actions. The influence of sex for each vitamin is also presented at each life stage to highlight the different daily requirements and effects.

The Predictive Role of Vitamin D Deficiency in Urinary Tract Infection at Reproductive Age in Women

BACKGROUND: Urinary tract infections (UTIs) are common health infections in pregnant women with high complications. Many of the worldwide population suffer from vitamin D deficiency (VDD) due to insufficient exposure to sunlight. The relationship between VDD and UTI and giving vitamin D supplementation contributes to preventing UTI. AIM: The present study aims to find the effect of VDD and UTIs in women of reproductive age as risk factors during pregnancy. METHODS: The samples were collected from May 2020 to February 2021 from gynecology clinic outpatients and private clinics in Basrah city. A 104 sample was collected from females of reproductive age between 15 and 45 years divided into three age groups suffering recurrent UTI and VDD. RESULTS: Of 104 women who followed up with UTIs during the study period, the deficiency of vitamin D levels in women was 62.5%. The levels of deficiency were significantly higher in the age group 25-34y is 71.1%, followed by 15-24y is 63.2%, and 35-45 y is 50% with mean 24 ± 6.8 years. In addition, the results showed the vitamin D levels at an insufficient level (30.8%) higher in the age group 35-45 y is 42.9% with a mean of 10 ± 1.2. Furthermore, the results showed that the vitamin D levels at an insufficient level (30.8%) higher in the age group 35–45 years are 42.9% with a mean of 10 ± 1.2. CONCLUSION: Our current study revealed that there is a clear correlation between women who suffer from VDD and UTIs, whether severe or frequent infection at reproductive age and this affects their fertility and pregnancy. In addition, the study concluded that adolescent girls and young women are the most vulnerable to VDD and UTIs.

Vitamin D level and fractures in children and adolescents: a systematic review and meta-analysis

INTRODUCTION

The aim of the study was to determine the relationship between vitamin D levels and the risk of bone fractures in children and adolescents.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane library databases were searched using subject and free words. The Newcastle-Ottawa scale form was used to assess literature quality. ReVman 5.2 and Stata 13.0 were used for statistical analyses. The results were expressed as the mean difference (MD)/odds ratio (OR) and 95% confidence interval (95% CI). The heterogeneity test was conducted according to I² and Q tests. Egger's test was used to evaluate publication bias.

RESULTS

Thirteen studies (3943 participants ≤ 18 years old) were included, and the quality of the literature was acceptable. Regarding the 25-hydroxyvitamin D (25OHD) level in the random effects model, the MD = - 0.12 ng/mL (95% CI: -1.93, 1.69), I² = 83%, and P < 0.00001, indicating large heterogeneity. Subgroup analyses were conducted according to vitamin D supplementation and 25OHD level, the sources of heterogeneity were not found. Regarding the proportion of subjects with vitamin D deficiency in the random effects model, OR = 1.09 (95% CI: 0.67, 1.79), I² = 79%, and P < 0.0001. By sensitivity analysis, after removing Al-Daghri's study, OR = 1.22 (95% CI: 0.96, 1.56), I² = 0%, and P = 0.64.

CONCLUSION

There is no relationship between vitamin D level and the risk of bone fractures in children and adolescents.

Exocrine pancreas insufficiency: clinical significance and approaches to correction from evidence medicine

Exocrine pancreatic insufficiency (EPI) is a common complication of both benign and malignant diseases of the pancreas, as well as a consequence of radical surgical operations on the pancreas and a whole range of other variable extra-pancreatic causes. In clinical practice in the adult population, most cases of EPI are associated with chronic pancreatitis, while in the pediatric population with cystic fibrosis. The regression of the production of digestive enzymes in EPI mediates the development of the syndrome of maldigestion and malabsorption, leading to the progressive development of malnutrition, the importance of which is often underestimated by practitioners. At the same time, the development of nutritional deficiency is not just a complication of EPI, but also has an important effect on the course of the underlying causative disease, worsening the prognosis and quality of life of the patient, and is also a proven risk factor for osteoporosis and sarcopenia. To date, compensation for the absolute deficiency of pancreatic enzymes using enzyme replacement therapy is the only possible way to correct the EPI and prevent nutritional deficiency.

Alfacalcidol improves the growth velocity in children with vitamin D deficiency/insufficiency: A single center retrospective cohort study

OBJECTIVES

To investigate the growth velocity-improving effects of vitamin D replacement therapy in pediatric patients diagnosed with vitamin D deficiency and insufficiency.

STUDY DESIGN

A retrospective cohort study was conducted in 34 pediatric patients diagnosed with vitamin D deficiency/insufficiency. Based on the clinical findings, the subjects were divided into two groups: a bowed leg (BL) group and a non-bowed leg (non-BL) group. After the initiation of alfacalcidol, the standard deviation score (SDS) of their heights, weights and growth velocities in each group were monitored.

RESULTS

The median age at the first visit was significantly lesser in the BL group (1.58 years old [interquartile range (IQR): 1.33, 2.17]) than that in the non-BL group (3.00 years old [IQR: 2.33, 3.67]). On the contrary, the SDS for height was significantly lower in the non-BL group (-2.27 [IQR: -2.63, -1.94]) than that in the BL group (-1.37 [IQR: -1.91, -1.07]). One-year treatment with alfacalcidol showed significant improvements in both height SDSs and growth velocity SDSs not only in the BL group but also in the non-BL group.

CONCLUSIONS

The current study revealed that vitamin D replacement therapy improved the growth rate in children with vitamin D deficiency/insufficiency, regardless of the presence of BL. This study emphasizes the importance of assessing the vitamin D status in children with poor growth rates and suggests that alfacalcidol could be a valid option for the treatment of short stature.

FGF23 and Bone and Mineral Metabolism

FGF23 is a phosphotropic hormone produced by the bone. FGF23 works by binding to the FGF receptor-Klotho complex. Klotho is expressed in several limited tissues including the kidney and parathyroid glands. This tissue-restricted expression of Klotho is believed to determine the target organs of FGF23. FGF23 reduces serum phosphate by suppressing the expression of type 2a and 2c sodium-phosphate cotransporters in renal proximal tubules. FGF23 also decreases 1,25-dihydroxyvitamin D levels by regulating the expression of vitamin D-metabolizing enzymes, which results in reduced intestinal phosphate absorption. Excessive actions of FGF23 cause several types of hypophosphatemic rickets/osteomalacia characterized by impaired mineralization of bone matrix. In contrast, deficient actions of FGF23 result in hyperphosphatemic tumoral calcinosis with high 1,25-dihydroxyvitamin D levels. These results indicate that FGF23 is a physiological regulator of phosphate and vitamin D metabolism and indispensable for the maintenance of serum phosphate levels.

Vitamin D supplementation for term breastfed infants to prevent vitamin D deficiency and improve bone health

BACKGROUND

Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants, children and adolescents. Vitamin D levels are low in breast milk and exclusively breastfed infants are at risk of vitamin D insufficiency or deficiency.

OBJECTIVES

To determine the effect of vitamin D supplementation given to infants, or lactating mothers, on vitamin D deficiency, bone density and growth in healthy term breastfed infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to 29 May 2020 supplemented by searches of clinical trials databases, conference proceedings, and citations.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs in breastfeeding mother-infant pairs comparing vitamin D supplementation given to infants or lactating mothers compared to placebo or no intervention, or sunlight, or that compare vitamin D supplementation of infants to supplementation of mothers.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 19 studies with 2837 mother-infant pairs assessing vitamin D given to infants (nine studies), to lactating mothers (eight studies), and to infants versus lactating mothers (six studies). No studies compared vitamin D given to infants versus periods of infant sun exposure. Vitamin D supplementation given to infants: vitamin D at 400 IU/day may increase 25-OH vitamin D levels (MD 22.63 nmol/L, 95% CI 17.05 to 28.21; participants = 334; studies = 6; low-certainty) and may reduce the incidence of vitamin D insufficiency (25-OH vitamin D < 50 nmol/L) (RR 0.57, 95% CI 0.41 to 0.80; participants = 274; studies = 4; low-certainty). However, there was insufficient evidence to determine if vitamin D given to the infant reduces the risk of vitamin D deficiency (25-OH vitamin D < 30 nmol/L) up till six months of age (RR 0.41, 95% CI 0.16 to 1.05; participants = 122; studies = 2), affects bone mineral content (BMC), or the incidence of biochemical or radiological rickets (all very-low certainty). We are uncertain about adverse effects including hypercalcaemia. There were no studies of higher doses of infant vitamin D (> 400 IU/day) compared to placebo. Vitamin D supplementation given to lactating mothers: vitamin D supplementation given to lactating mothers may increase infant 25-OH vitamin D levels (MD 24.60 nmol/L, 95% CI 21.59 to 27.60; participants = 597; studies = 7; low-certainty), may reduce the incidences of vitamin D insufficiency (RR 0.47, 95% CI 0.39 to 0.57; participants = 512; studies = 5; low-certainty), vitamin D deficiency (RR 0.15, 95% CI 0.09 to 0.24; participants = 512; studies = 5; low-certainty) and biochemical rickets (RR 0.06, 95% CI 0.01 to 0.44; participants = 229; studies = 2; low-certainty). The two studies that reported biochemical rickets used maternal dosages of oral D3 60,000 IU/day for 10 days and oral D3 60,000 IU postpartum and at 6, 10, and 14 weeks. However, infant BMC was not reported and there was insufficient evidence to determine if maternal supplementation has an effect on radiological rickets (RR 0.76, 95% CI 0.18 to 3.31; participants = 536; studies = 3; very low-certainty). All studies of maternal supplementation enrolled populations at high risk of vitamin D deficiency. We are uncertain of the effects of maternal supplementation on infant growth and adverse effects including hypercalcaemia. Vitamin D supplementation given to infants compared with supplementation given to lactating mothers: infant vitamin D supplementation compared to lactating mother supplementation may increase infant 25-OH vitamin D levels (MD 14.35 nmol/L, 95% CI 9.64 to 19.06; participants = 269; studies = 4; low-certainty). Infant vitamin D supplementation may reduce the incidence of vitamin D insufficiency (RR 0.61, 95% CI 0.40 to 0.94; participants = 334; studies = 4) and may reduce vitamin D deficiency (RR 0.35, 95% CI 0.17 to 0.72; participants = 334; studies = 4) but the evidence is very uncertain. Infant BMC and radiological rickets were not reported and there was insufficient evidence to determine if maternal supplementation has an effect on infant biochemical rickets. All studies enrolled patient populations at high risk of vitamin D deficiency. Studies compared an infant dose of vitamin D 400 IU/day with varying maternal vitamin D doses from 400 IU/day to > 4000 IU/day. We are uncertain about adverse effects including hypercalcaemia.

AUTHORS' CONCLUSIONS

For breastfed infants, vitamin D supplementation 400 IU/day for up to six months increases 25-OH vitamin D levels and reduces vitamin D insufficiency, but there was insufficient evidence to assess its effect on vitamin D deficiency and bone health. For higher-risk infants who are breastfeeding, maternal vitamin D supplementation reduces vitamin D insufficiency and vitamin D deficiency, but there was insufficient evidence to determine an effect on bone health. In populations at higher risk of vitamin D deficiency, vitamin D supplementation of infants led to greater increases in infant 25-OH vitamin D levels, reductions in vitamin D insufficiency and vitamin D deficiency compared to supplementation of lactating mothers. However, the evidence is very uncertain for markers of bone health. Maternal higher dose supplementation (≥ 4000 IU/day) produced similar infant 25-OH vitamin D levels as infant supplementation of 400 IU/day. The certainty of evidence was graded as low to very low for all outcomes.

Vitamin D deficiency as a risk factor for urinary tract infection in women at reproductive age

Vitamin D deficiency is a pandemic problem and an ever-increasing issue in human nutrition and health. Vitamin D (serum 25-hydroxyvitamin D) deficiency causes many health problems such as autoimmune diseases, Crohn's disease, diabetes, inflammation, asthma, hypertension, and cancer. Vitamin D3 (cholecalciferol) deficiency has been documented as a persistent problem among adults, children, and elderly persons in most of the countries. Our main objective of this study was to determine the hypothesis that the vitamin D deficiency among women can lead to them developing frequent urinary tract infections. Vitamin D has a potential role in immune regulation and it prevents infections especially urinary tract infections (UTI). Therefore it has positive regulatory role in both acute and recurrent infections especially in women of reproductive ages. As women at this age group have specific differences in their urinary tract and the reproductive organ anatomy, make them more prone for micro-organisms' invasion, The present study was carried out to ascertain certain relation between serum 25-hydroxyvitamin D levels and UTI in women while contemplating the significance of knowing the risk factors associated with UTI and also finding ways to avoid serious complications. 75 women with (case group) UTI were differentiated with 35 healthy with no UTI (control group) and 40 women with UTI and their serum 25-hydroxyvitamin D levels were checked in a case control study. The women were between at 17-52 years of age. Using ELISA, Serum 25-hydroxyvitamin D levels were measured. Analysis and comparison of the results were done among the two groups. Vitamin D mean levels in the case group was considerably lower when in comparison with the control group (11.09 ± 7.571 ng/mL vs. 24.08 ± 11.95 ng/mL, P < 0.001).

The Association Between Serum 25-Hydroxyvitamin D Levels and Patients With Allergic Rhinitis

Introduction Many studies have suggested a link between vitamin D deficiency and the development of other atopic diseases like allergic rhinitis (AR). AR can lead to sleep disturbance, fatigue, depressed mood, and compromised cognitive function, which can impair the quality of life and productivity in many people. Objective We aimed to determine the association between vitamin D levels and AR and the effect of vitamin D on atopy markers. Methods All patients with AR who were diagnosed, treated, and followed up at the King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia from January 2012 to January 2020 were included in the study. Our exclusion criteria were as follows: pediatric patients, patients with insufficient follow-up data, patients with no atopy markers, patients with comorbid conditions affecting their serum vitamin D levels, and patients with a history of taking medications that affect serum vitamin D levels. Results Fifty-five adult patients with AR were included in the study. Patients with vitamin D deficiency were more likely to have uncontrolled AR. Regarding the effect of vitamin D deficiency on atopy markers, there was no statistically significant relationship between vitamin D deficiency and serum immunoglobulin E (IgE) levels. However, serum eosinophil levels were significantly higher in patients with vitamin D deficiency. Conclusion Our results showed that vitamin D deficiency is strongly associated with uncontrolled AR; there was a statistically significant relationship between vitamin D deficiency and eosinophil levels, but no significant relationship between vitamin D deficiency and serum IgE was found.

The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression

OBJECTIVE

Vitamin D (vitD) deficiency is a global childhood health problem. Food fortification is a promising strategy to curb vitD deficiency. We aimed to assess the effectiveness of utilizing vitD fortification in staple foods to improve 25hydroxyvitamin D (25(OH)D) concentration and to reduce the prevalence of vitD deficiency among healthy children.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the use of vitD fortified food products compared to no fortification among healthy children aged 1-18 years old. We searched Medline, Embase, Global Health, and Cochrane (CENTRAL) databases from database inception until May 2019. Independently, six reviewers in pairs screened titles and abstracts, assessed the full text for eligibility, and performed data extraction and quality assessment. The primary outcome is the impact of fortification on 25(OH)D concentration. The secondary outcomes included the impact of fortification on the prevalence of vitD deficiency, school performance, cognitive function, school absences, infection rate, hospital admission length, and compliance with fortified food product consumption.

RESULTS

We identified 2229 articles. After assessing eligibility, 20 RCTs met the inclusion criteria. The eligible RCTs assessed the fortification of milk, cereal, juice, bread, yogurt, and cheese compared with no fortification. All RCTs, except for three, had a low risk of bias. Food fortification improved 25(OH)D concentration by a mean difference (MD) of 15.51 nmol/L (95% confidence interval (CI) 6.28, 24.74; I² = 99%), which resulted in a mean increase of 3 nmol/l for every 100 IU of vitD, when adjusted for baseline 25(OH)D concentration and country latitude. Additionally, the prevalence of vitD deficiency decreased by a risk ratio of 0.53 (95% CI 0.41, 0.69; I² = 95%), and cognitive function improved by a MD of 1.22 intelligence quotient (IQ) points (95% CI 0.65, 1.79; I² = 0%). The overall evidence quality was high.

CONCLUSION

VitD food fortification is an effective way to improve 25(OH)D concentration, prevent vitD deficiency, and improve IQ levels.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017057631.

Vitamin D in Adolescents: A Systematic Review and Narrative Synthesis of Available Recommendations

PURPOSE

Practical guidelines help clinicians make their preventive and therapeutic choices and improve care management. Our purpose was to collect and synthesize available recommendations concerning vitamin D in adolescents (aged 10-19 years).

METHODS

We searched PubMed, EMBASE, and Cochrane databases from inception to February 5, 2019, for guidance published by different professional associations and governments. We also searched the reference lists of identified recommendations and explored the gray literature using Web search engines. We organized documents by theme: dietary requirements, thresholds, prophylactic supplementation, and treatment of deficiency.

RESULTS

A total of 32 documents were identified. Most of them targeted the general population and not specifically the age group of adolescents. There is a general agreement that adolescents should not have serum 25-hydroxyvitamin D concentrations below 25-30 nmol/L to avoid poor bone health. However, there is lack of consensus on the optimal concentration to aim for, levels varying between 25 nmol/L and 150 nmol/L. Adequate nutritional requirements of vitamin D are also subject to debate with values ranging between 200 IU/d and 1,000 IU/d. The upper tolerable intake is estimated at 4,000 IU/d by all study groups. Certain associations recommend routine vitamin D supplementation in adolescents. The recommended daily preventive doses vary between 400 IU and 4,000 IU, depending on season, skin pigmentation, sun exposure, consumption of vitamin D-fortified foods, body mass index, and coexistence of certain medical conditions. In case of deficiency, different therapeutic regimens of oral vitamin D are proposed depending on the presence of illness and/or the baseline serum 25-hydroxyvitamin D concentrations. Duration of the treatment varies between 4 weeks and 3 months. A maintenance dose is generally recommended after treatment.

CONCLUSIONS

At present, there is no consensus among the different societies about vitamin D needs during adolescence. Stronger, evidence-based guidance is needed to inform clinical practice.

Serum 25-hydroxyvitamin D concentrations in 16-year-old Icelandic adolescent and its association with bone mineral density

OBJECTIVE

The aim of the study was to assess the potential association between serum 25-hydroxyvitamin D (25(OH)D) and whole-body bone mineral density (BMD) among 16-year-old adolescents and to study the prevalence of 25(OH)D insufficiency, defined as concentration under 50 nmol/l.

DESIGN

A cross-sectional study.

SETTING

Reykjavik, Iceland, latitude 64°08'N. Measurements took place in the Icelandic Heart Association's research lab during April-June 2015.

PARTICIPANTS

In total, 411 students in Reykjavik, Iceland, were invited to participate, 315 accepted the invitation (76·6 %) and 289 had valid data (mainly Caucasian).

RESULTS

25(OH)D < 50 nmol/l was observed in 70 % of girls and 66·7 % of boys. 25(OH)D ≥ 50 nmol/l was significantly associated with higher whole-body BMD after adjusting for the influence of sex, height, fat mass and lean mass. A linear relationship between 25(OH)D and whole-body BMD was significant for 25(OH)D < 50 nmol/l (n 199, P < 0·05) but NS for 25(OH)D ≥ 50 nmol/l (n 86, P = 0·48).

CONCLUSIONS

Our results are in line with some but not all previous studies on the relationship between BMD and 25(OH)D in adolescents. The observed difference in BMD between those with above v. below a 25(OH)D concentration of 50 nmol/l was of about a fifth of one SD, which may have a clinical relevance as one SD decrease in volumetric BMD has been associated with a 89 % increase in 2 years risk of fracture. Icelandic adolescents should be encouraged to increase their vitamin D intake as it is possible that their current intake is insufficient to achieve optimal peak bone mass.

Assessment of selected nutrient intake by Polish preschool children compared to dietary recommendations: a meta-analysis

INTRODUCTION

In recent years a steady increase in the number of obese people has been observed worldwide. This problem is also increasingly applicable to children and adolescents. In this study, we conducted a meta-analysis of studies carried out in Poland over ten years (2005-2015) which analysed the diet of preschool children and assessed how significantly it affects the prevention of diet-dependent disease.

MATERIAL AND METHODS

Two of the researchers independently performed a systematic search of Medline, Embase, Google Scholar, and the Polish Medical Bibliography to find studies published between 2005 and 2015. The variance of the means of differences between selected factors in relation to dietary guidelines and standards for preschool children was estimated by summing the individual variances of means. The means of differences between selected factors across the studies were pooled using random-effects model meta-analysis.

RESULTS

The analysis included a total of 2095 children. Mean protein content in the diet of children studied is 111% higher than indicated in dietary recommendations for this age group; mean consumption of carbohydrates in the study group is 24% higher than recommended. In moderately high calorie diets, analysis showed that the recommended norm is exceeded by 47%, CE 0.77, p < 0.001.

CONCLUSIONS

Nutrient intake is not compliant with recommendations for this age group and could not only inhibit physical development, but also increase the risk of diet-dependent diseases.

Effects of vitamin D3 supplementation on serum 25(OH)D concentration and strength in athletes: a systematic review and meta-analysis of randomized controlled trials

Background

The purpose of this systematic review and meta-analysis is to investigate the effects of vitamin D3 supplementation on skeletal muscle strength in athletes. Vitamin D3 supplements or vitamin D3 fortified foods always have claims for bringing people health benefits including bone and muscle health. An up-to-date rigorous systematic review and meta-analysis is important to better understand the effect of vitamin D3 supplementation on muscle strength.

Methods

English written randomized controlled trials (RCTs) that looked at effects of vitamin D3 supplementation on muscle strength in healthy athletes were searched using three databases (PubMed, Embase and Cochrane Library). Serum 25(OH)D above 30 ng/mL is considered to be sufficient in this systematic review and meta-analysis.

Results

Five RCTs with 163 athletes (vitamin D3 n = 86, placebo n = 77) met inclusion criteria. Fourteen athletes were lost to follow-up and 149 athletes (vitamin D3 n = 80, placebo n = 69) were documented with complete result. Among athletes with baseline serum 25(OH)D values suggesting insufficiency, vitamin D3 daily dosage at 5000 IU for over 4 weeks led to a serum 25(OH)D concentration of 31.7 ng/mL. Athletes with sufficient serum 25(OH)D level at baseline were recruited in only one study, and the participants of which were assigned to either vitamin D3 at a daily dosage of 3570 IU or placebo for 12 weeks, their serum 25(OH)D sufficiency (VD: 37.2 ± 7.6 vs. 45.6 ± 7.6; PL: 38 ± 6.8 vs. 32 ± 8.4) was well maintained above the cut-off boundary. One repetition maximum Bench Press (1-RM BP) was not improved significantly (SMD 0.07, 95% CI: − 0.32 to 0.47, P = 0.72) and there was no significant increase in maximal quadriceps contraction (SMD -2.14, 95% CI: − 4.87 to 0.59, P = 0.12). Furthermore, there was no significant overall effect of vitamin D3 intervention on muscle strength in this meta-analysis (SMD -0.75, 95% CI: − 1.82 to 0.32, P = 0.17).

Conclusion

Although, serum 25(OH)D concentrations after supplementation reached sufficiency was observed, muscle strength did not significantly improve at this point of current meta-analysis. Additional well-designed RCTs with large number of participants examined for the effect of vitamin D3 supplementation on serum 25(OH)D concentrations, muscle strength in a variety of sports, latitudes and diverse multicultural populations are needed.

Impact of multi-micronutrient supplementation on lipidemia of children and adolescents

BACKGROUND

Micronutrient supplementation has been extensively explored as a strategy to improve health and reduce risk of chronic diseases. Fat-soluble vitamins like A and E with their antioxidant properties and mechanistic interactions with lipoproteins, have potentially a key impact on lipid metabolism and lipidemia.

OBJECTIVE

The impact of micronutrients on lipid metabolism requires further investigation including characterization of plasma lipidome following supplementation and any cause-effect on circulating lipids.

DESIGN

In this study, we elucidate the effect and associations of a multi-micronutrient intervention in Brazilian children and teens with lipoprotein alterations and lipid metabolism.

RESULTS

Our analysis suggests a combination of short and long-term impact of supplementation on lipid metabolism, potentially mediated primarily by α-tocopherol (vitamin E) and retinol (vitamin A). Among the lipid classes, levels of phospholipids, lysophospholipids, and cholesterol esters were impacted the most along with differential incorporation of stearic, palmitic, oleic and arachidonic acids. Integrated analysis with proteomic data suggested potential links to supplementation-mediated alterations in protein levels of phospholipases and pyruvate dehydrogenase kinase 1 (PDK1).

CONCLUSIONS

Associations between the observed differences in lipidemia, total triglyceride, and VLDL-cholesterol levels suggest that micronutrients may play a role in reducing these risk factors for cardiovascular disease in children. This would require further investigation.

Serum vitamin D concentrations in young Turkish women with primary dysmenorrhea: A randomized controlled study

OBJECTIVE

This study aims to investigate the possible role of vitamin D deficiency in primary dysmenorrhea by assessing serum 25-hydroxyvitamin D₃ levels in a cohort which includes young Turkish women with primary dysmenorrhea and healthy controls.

MATERIALS AND METHODS

A total of 683 women who were aged between 18 and 25 years and who were consecutively admitted to the study center were eligible. After the exclusion of 55 women, 184 women with primary dysmenorrhea were randomly assigned into the dysmenorrhea group and 184 women without dysmenorrhea were randomly allocated into the control group.

RESULTS

The dysmenorrhea group had significantly less consumption of dairy products (p = 0.001), lower serum calcium (p = 0.001), lower serum vitamin D (p = 0.001) and higher serum parathyroid hormone (p = 0.001) than those of the control group. Hyperparathyroidism was significantly less frequent whereas vitamin D deficiency was significantly more frequent in the dysmenorrhea group (p = 0.001 for each). The dysmenorrhea patients with vitamin D deficiency had significantly higher visual analogue scale (VAS) scores (p = 0.001). Depression, irritability, mood swings, fatigue, headache and breast tenderness were significantly more frequent in the vitamin D deficiency group (p < 0.05 for all). The VAS scores of the dysmenorrhea patients correlated positively and significantly with serum parathyroid hormone levels (r = 0.666, p = 0.001) whereas these VAS scores correlated negatively and significantly with serum vitamin D levels (r = -0.713, p = 0.001).

DISCUSSION

The significant and positive correlation between vitamin D levels and VAS scores and the significant reduction in serum vitamin D levels of the dysmenorrhea patients designate the possible role of vitamin D deficiency in the primary dysmenorrhea.

Previous Adolescent Pregnancy and Breastfeeding Does Not Negatively Affect Bone Mineral Density at the Age of Peak Bone Mass

PURPOSE

To determine bone mineral density (BMD) at the age of peak bone mass in women who previously experienced pregnancy and breastfeeding during adolescence.

MATERIALS AND METHODS

In this retrospective study, female volunteers aged 24-30 years who were pregnant during the age of 15-19 years and have had one to two babies were recruited. All of them experienced breastfeeding without history of bone- or calcium-related problems, such as fracture or low calcium intake. BMD was determined at the femur and L1-L4 spine by dual-energy X-ray absorptiometry.

RESULTS

We found that both volunteers who previously experienced breastfeeding and age-matched control volunteers had similar BMD at the L1-L4 spines and femora. Further analysis for site-specific changes of lumbar and femoral BMDs showed that the values of the breastfeeding group were not different from those of the control group except at L1 and L2, where BMD values were greater in breastfeeding group compared with the control group. At both femoral and vertebral sites, T- and Z-scores were apparently similar between the two groups. In addition, the BMD at peak bone mass had no significant correlation with breastfeeding duration.

CONCLUSIONS

Teenage pregnancy and breastfeeding did not negatively affect BMD later at the age of peak bone mass. Therefore, breastfeeding can be encouraged in teenage mothers.

Vitamin D in pediatric age: consensus of the Italian Pediatric Society and the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Federation of Pediatricians

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur.Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.

Birth size, body composition, and adrenal androgens as determinants of bone mineral density in mid-childhood

BackgroundBirth weight has an impact on adult bone mass. Higher birth weight is associated with greater bone mineral content (BMC) and children born small for gestational age (SGA) are at an increased risk for impaired accrual of bone mass. Our aim was to study whether the impact of birth size or early childhood growth on bone mass is visible already in mid-childhood.MethodsWe studied 49 children born large for gestational age (LGA), 56 children born appropriate for gestational age (AGA), and 23 children born SGA at 5.0-8.7 years of age. Body composition was assessed by whole-body dual-energy X-ray absorptiometry. Fasting blood samples and anthropometric data were collected.ResultsThe children born SGA had lower bone mineral density (BMD) Z-score (P<0.001) and age- and sex-adjusted BMD (P<0.005) than the LGA and AGA children. Adjusted BMC, muscle mass, and body fat percentage (%BF) did not differ between the study groups. Muscle mass, BMI SD score (SDS), %BF, and serum dehydroepiandrosterone sulfate (DHEAS) concentration were the strongest predictors of high BMD in mid-childhood.ConclusionSGA-born children had lower BMD in mid-childhood compared with AGA- and LGA-born ones. Muscle mass or BMI SDS, %BF, and DHEAS were significant predictors of childhood BMD.

Foetal, neonatal and child vitamin D status and enamel hypomineralization

Objectives

Recent literature suggested that higher vitamin D concentrations in childhood are associated with a lower prevalence of molar incisor hypomineralization (MIH). As tooth development already starts in utero, we aimed to study whether vitamin D status during foetal, postnatal and childhood periods is associated with the presence of hypomineralized second primary molars (HSPMs) and/or MIH at the age of six.

Methods

Our study was embedded in the Generation R Study, a population‐based, prospective cohort from foetal life onwards in Rotterdam, the Netherlands. HSPMs and MIH were scored from intraoral photographs of the children at their age of six. Serum 25(OH)D concentrations were measured at three points in time, which resulted in three different samples; mid‐gestational in mothers’ blood (n = 4750), in umbilical cord blood (n = 3406) and in children's blood at the age of 6 years (n = 3983).

Results

The children had a mean (±SD) age of 6.2 (±0.5) years at the moment of taking the intraoral photographs. After adjustment for confounders, no association was found between foetal 25(OH)D concentrations and the presence of HSPMs (OR 1.02 per 10 nmol/L higher 25(OH)D, 95% CI: 0.98‐1.07) or MIH (OR 1.05 per 10 nmol/L increase, 95% CI: 0.98‐1.12) in 6‐year‐olds. A higher 25(OH)D concentration in umbilical cord blood resulted in neither lower odds of having HSPM (OR 1.05, 95% CI: 0.98‐1.13) nor lower odds of having MIH (OR 0.95, 95% CI: 0.84‐1.07) by the age of six. Finally, we did not find higher 25(OH)D concentrations at the age of six to be associated with a significant change in the odds of having HSPM (OR 0.97, 95% CI: 0.92‐1.02) or MIH (OR 1.07, 95% CI: 0.98‐1.16).

Conclusions

25(OH)D concentrations in prenatal, early postnatal and later postnatal life are not associated with the presence of HPSMs or with MIH at the age of six. Future observational research is required to replicate our findings. Furthermore, it is encouraged to focus on identifying other modifiable risk factors, because prevention of hypomineralization is possible only if the causes are known.

The optimal dosage regimen of vitamin D supplementation for correcting deficiency in adolescents: a pilot randomized controlled trial

BACKGROUND/OBJECTIVES

Vitamin D deficiency is common in adolescents but the optimal dosage regimen for correcting deficiency is unknown. To test the safety and efficacy of two different vitamin D dosage regimens to correct vitamin D deficiency in adolescents.

SUBJECTS/METHODS

In this 12-month, double-blind, randomized placebo-controlled trial, 28 adolescents (serum 25 hydroxyvitamin D (25(OH)D) of 21 to 50 nmol/L) were randomly assigned to one of three groups: monthly (n = 9; vitamin D3 50,000 IU orally monthly plus three placebo tablets 3-monthly), 3-monthly (n = 9; 150,000 IU (3 × 50,000 IU tablets) 3-monthly and placebo orally monthly), or placebo (n = 10; placebo monthly and three placebo tablets 3-monthly). Serum 25(OH)D was measured at baseline, 3, 6 and 12 months.

RESULTS

Two participants withdrew after their baseline measurement from the 3-monthly group. At 12 months, one participant was deficient (≤50 nmol/L) in both the monthly and 3-monthly groups, whereas six out of ten in the placebo remained deficient (P = 0.055). At 12 months, the average serum 25(OH)D levels for the monthly, 3-monthly and placebo groups were 76.4, 64.7 and 49.7 nmol/L, respectively (P < 0.001 and P = 0.04 for differences between monthly and placebo groups and 3-monthly and placebo groups respectively, after adjustment for age, sex and seasonal variation). Adherence was 100% and adverse events were minor.

CONCLUSIONS

Both 50,000 IU monthly and 150,000 IU 3-monthly of vitamin D3 safely and effectively corrects vitamin D deficiency in adolescents. These data provide treatment options which can be used by health practitioners to tailor vitamin D dosage regiments according to patient preference and context.

Does vitamin D supplementation improve bone density in vitamin D-deficient children? Protocol for an individual patient data meta-analysis

INTRODUCTION

Our previous study-level (aggregate data) meta-analysis suggested that vitamin D supplements may be beneficial for bone density specifically in children with vitamin D deficiency. However, the misclassification of vitamin D status inherent in study-level data means that the results are not definitive and cannot provide an accurate assessment of the size of any effect. Therefore, we propose to undertake an individual patient data (IPD) meta-analysis to determine whether the effect of vitamin D supplementation on bone density in children differs according to baseline vitamin D status, and to specifically estimate the effect of vitamin D in children who are vitamin D deficient.

METHODS AND ANALYSIS

This study has been designed to adhere to the Preferred Reporting Items for Systematic Review and Meta-Analyses of IPD statement. We will include randomised placebo-controlled trials of vitamin D supplementation reporting bone density outcomes at least 6 months after the study commenced in children and adolescents (aged <20 years) without coexistent medical conditions or treatments causing osteoporosis. We will update the search of the original review to cover the period 2009-2017, using the same methods as the original review. Fully anonymised data on all randomised patients will be requested. Outcomes will be femoral neck, total hip, lumbar spine and proximal and distal forearm bone mineral density, and total body bone mineral content. A two-stage IPD meta-analysis will be used to examine the effect of baseline serum 25-hydroxyvitamin D (25(OH)D) on treatment effect for each bone density outcome. Restricted maximum likelihood will be used to estimate the random-effects meta-analysis models, with 95% CI for summary effects. Heterogeneity will be assessed by I² and potential publication bias (small-study effects) and availability bias by funnel plots, Egger's test and Peter's test.

ETHICS AND DISSEMINATION

Ethics approval will not be required as the data are to be used for the primary purpose for which they were collected and all original individual studies had ethics approval. Results of the IPD meta-analysis will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42017068772.

Associations of Low Vitamin D and Elevated Parathyroid Hormone Concentrations With Bone Mineral Density in Perinatally HIV-Infected Children

BACKGROUND

Perinatally HIV-infected (PHIV) children have, on average, lower bone mineral density (BMD) than perinatally HIV-exposed uninfected (PHEU) and healthy children. Low 25-hydroxy vitamin D [25(OH)D] and elevated parathyroid hormone (PTH) concentrations may lead to suboptimal bone accrual.

METHODS

PHIV and PHEU children in the Pediatric HIV/AIDS Cohort Study had total body (TB) and lumbar spine (LS) BMD and bone mineral content (BMC) measured by dual-energy x-ray absorptiometry; BMD z-scores (BMDz) were calculated for age and sex. Low 25(OH)D was defined as ≤20 ng/mL and high PTH as >65 pg/mL. We fit linear regression models to estimate the average adjusted differences in BMD/BMC by 25(OH)D and PTH status and log binomial models to determine adjusted prevalence ratios of low 25(OH)D and high PTH in PHIV relative to PHEU children.

RESULTS

PHIV children (n = 412) were older (13.0 vs. 10.8 years) and more often black (76% vs. 64%) than PHEU (n = 207). Among PHIV, children with low 25(OH)D had lower TB-BMDz [SD, -0.38; 95% confidence interval (CI), -0.60 to -0.16] and TB-BMC (SD, -59.1 g; 95% CI, -108.3 to -9.8); high PTH accompanied by low 25(OH)D was associated with lower TB-BMDz. Among PHEU, children with low 25(OH)D had lower TB-BMDz (SD, -0.34; 95% CI, -0.64 to -0.03). Prevalence of low 25(OH)D was similar by HIV status (adjusted prevalence ratio, 1.00; 95% CI, 0.81 to 1.24). High PTH was 3.17 (95% CI, 1.25 to 8.06) times more likely in PHIV children.

CONCLUSIONS

PHIV and PHEU children with low 25(OH)D may have lower BMD. Vitamin D supplementation trials during critical periods of bone accrual are needed.

Vitamin D Modulation of TRAIL Expression in Human Milk and Mammary Epithelial Cells

The vitamin D levels in mothers affect the health status of both the mother and breastfeeding infant. Vitamin D deficient mothers’ infants are prone to rickets. While tumor necrosis factor-related apoptosis inducing ligand (TRAIL) has been implicated in cellular growth/apoptosis, immune cell function and bone-resorbing osteoclast formation, the expression of TRAIL in human milk as a function of vitamin D status in mothers remains unknown. We hypothesized that vitamin D deficiency alters TRAIL protein levels in human breast milk and mammary epithelial cells. Milk from vitamin D deficient mothers showed high levels of TRAIL (α and β) proteins compared to milk from vitamin D replete women. Western blot analysis of total cell lysate obtained from normal human mammary epithelial (HME-1) cells treated with variable doses (0–20 nM) of vitamin D for 24 h demonstrated that low levels (0.5 to 5 nM) significantly increased the TRAIL α but no change in β expression. In contrast, vitamin D at 20 nM concentration suppressed the expression of both TRAIL α and β proteins. Consistently, vitamin D regulated TRAIL mRNA expression in HME-1 cells. Our results indicate that vitamin D status in mothers modulates TRAIL expression in breast milk, which may have implications for both mother and infant health.

Vitamin D and Fracture Risk in Early Childhood: A Case-Control Study

The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009-April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (<2 cups/day vs. 2 cups/day: aOR = 0.95 (95% CI: 0.60, 1.52); >2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25, 0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children.

Vitamin D Deficiency in Pediatric Fracture Patients: Prevalence, Risk Factors, and Vitamin D Supplementation

OBJECTIVE

Although vitamin D levels are not routinely monitored in pediatric fracture patients, identification of children with a vitamin D deficiency may be clinically relevant because of the potential role of vitamin D in fracture healing. This study aimed to determine the prevalence of vitamin D deficiency in a pediatric fracture population and to identify risk factors for deficiency.

METHODS

All pediatric patients (<18 years) who were treated for a fracture of the upper or lower extremity from September 2012 to October 2013 in the outpatient setting of a level one trauma center were included in this cross-sectional study. Vitamin D deficiency was defined as a serum calcidiol <50 nmol/L. Potential risk factors for vitamin D deficiency were analysed using multivariable logistic regression analysis.

RESULTS

A total of 108 boys (58%) and 79 girls, of a mean age 11.1 years (standard deviation 3.9), who had undergone 189 fractures were included in the study. Sixty-four children (34%) were vitamin D deficient. Of those with follow-up measurements, 74% were no longer deficient after supplementation. Vitamin D status did not influence the occurrence of complications during fracture treatment. Independent risk factors for vitamin D deficiency were older age, season (spring), and a non-Caucasian skin type.

CONCLUSION

Clinicians who treat children with a fracture should inform patients and parents on vitamin D supplementation. Vitamin D measurement and supplementation may be needed for children with a non-Caucasian skin type or for those who present with a fracture during spring months.

Beneficial Effects of UV-Radiation: Vitamin D and beyond

Aside from its well-known effects on bone and mineral metabolism, vitamin D may also play an important role in extra-skeletal processes like immunologic diseases, cancer, or cardiovascular diseases. Even though meta-analyses showed that vitamin D supplementation reduces fractures, falls, and overall mortality, its potential benefits did not find universal acclaim. Several health care authorities published Recommended Dietary Allowances (RDAs) for vitamin D, most of them ranging from 600 to 800 international units (IU) per day, corresponding to a serum level of 25-hydroxyvitamin D of at least 20 ng/mL (50 nmol/L). However, studies conducted in the general population revealed a much lower overall intake of vitamin D than the proposed RDAs. Thus, strategies to increase the vitamin D intake in the general population, e.g., food fortification or vitamin D supplementation, are needed to match the existing evidence and recommendations. Therefore, several currently ongoing projects aim to investigate the effect of vitamin D supplementation in the general population and try to establish food-based solutions to improve vitamin D status.

Factors influencing bone mass accrual: focus on nutritional aspects

Until recently, much of the research exploring the role of nutrition on bone mass accrual has focused on single nutrients. Although randomised controlled trials have provided key information about the effects of calcium and vitamin D on bone, they also have limitations, e.g. generalisation, implementation of the results and long-term consequences. Human subjects do not eat single nutrients, but foods, and describing healthy food patterns for optimising bone mineral accrual is warranted. Recent advances in research suggest that the effects of whole diet are larger than those of single nutrients on bone health. Research should focus on younger age groups to identify the life-course determinants of osteoporosis during prenatal, infancy, childhood and adolescence that would help to maximise peak bone mass. Food patterns that describe the variability, quality and choices of individuals give broader insight and may provide new strategies for preventing osteoporosis.

Study of the Determinants of Vitamin D Status in Pediatric Patients With Osteogenesis Imperfecta

OBJECTIVE

Vitamin D is essential to the development and maintenance of the skeleton, especially for children with bone disorders such as osteogenesis imperfecta (OI). We evaluated serum 25-hydroxyvitamin D (25-OHD) levels to assess the relationship between determinants of vitamin D status in pediatric patients with OI.

METHODS

This cross-sectional study evaluated sex, age, weight, height, body mass index, OI type, sunscreen use, season of assessment, sun exposure, vitamin D and calcium supplementation, bisphosphonate treatment, bone mineral density (BMD), milk and soda consumption, mobility, and time of sedentary activity. Levels of serum 25-OHD, calcium, parathyroid hormone (PTH), phosphorus, and alkaline phosphatase (ALP) were analyzed. Serum levels of 25-OHD were classified according to sufficient (>30 ng/ml or 75 nmol/L), insufficient (20-30 ng/ml or 50-75 nmol/L), moderately deficient (20-10 ng/ml or 50-25 nmol/L), and severely deficient (<10 ng/ml or 25 nmol/L).

RESULTS

Fifty-two patients were included and 46 (88.4%) were classified as having insufficient or deficient 25-OHD. An inverse correlation between serum 25-OHD and time of sedentary activity (r = -0.597, p < 0.001) and a positive correlation with height (r = 0.521, p = 0.046) and whole body BMD (r = 0.586, p = 0.022) were observed. A significant difference between the number of glasses of milk consumed (p = 0.010) was observed.

CONCLUSION

To optimize bone health, patients with OI need to be educated regarding habits that can improve serum 25-OHD levels, such as a reduction in periods of inactivity, the importance of sun exposure, and increasing consumption of milk and fortified dairy products.

Serum 25-Hydroxyvitamin D Levels: Variability, Knowledge Gaps, and the Concept of a Desirable Range

Hypovitaminosis D is prevalent worldwide but proportions vary widely between regions, depending on genetic and lifestyle factors, the threshold to define deficiency, and accuracy of 25-hydroxyvitamin D (25OHD) assays used. Latitude, pollution, concealing clothing, sun exposure, gender, dietary habits, and lack of government regulation account for up to 50% in variations in serum 25OHD levels, whereas genetic polymorphisms in the vitamin D pathway account for less than 5%. Organizations/societies have developed guidelines for recommended desirable 25OHD levels and vitamin D doses to reach them, but their applicability across age groups and populations are still debated. This article and the accompanying online Supporting Information highlight sources of variations in circulating 25OHD levels, uncertainties and knowledge gaps, and analytical problems facing 25OHD assays, while keeping efficacy and safety data as the dominant factors when defining a desirable range for 25OHD levels. We propose a desirable range of 20 to 40 ng/mL (50 to 100 nmol/L), provided precise and accurate assays are used. Although slightly lower levels, 15 to 20 ng/mL, may be sufficient for some infants and adults, higher levels, 40 to 60 ng/mL, may still be safe. This desirable range allows physicians to tailor treatment while taking season, lifestyle, vitamin D intake, and other sources of variation into account. We reserve 25OHD measurements for at-risk patients, defined by disease or lifestyle, and the use of 25OHD assays calibrated against the recommended international standards. Most target groups reach desirable target levels by a daily intake of 400 to 600 IU for children and 800 IU for adults. A total daily allowance of vitamin D of up to 1000 IU in the pediatric age groups, and up to 2000 IU in adults, tailored to an individual patient risk profile, is probably safe over long durations. Additional data are needed to validate the proposed range and vitamin D doses, especially in children, pregnant women, and non-white populations.

Dietary intake in 6-year-old children from southern Poland: part 2--vitamin and mineral intakes

BACKGROUND

Studies on vitamin and mineral intakes in children are very important: firstly because of the high prevalence of diet-related diseases and secondly because of the widespread consumption of highly processed foods which are characterised by high energy content and low density of essential nutrients. Therefore, the purpose of this study was to analyse vitamin and mineral intakes in 6-year-old children from southern Poland.

METHODS

Vitamin and mineral intakes were estimated from a three-day food record in 120 children, 64 girls and 56 boys, aged 6 years. Nutrient densities were estimated as amounts per 1000 kcal (4185 kJ) of energy intake. Statistical analysis was carried out by means of the IBM SPSS Statistics computer programme, version 19. The studied population was divided according to gender.

RESULTS

Intakes of folic acid (μg/1000 kcal) and vitamin C (mg, mg/1000 kcal) were significantly higher in girls. Nutrient densities for all vitamins were higher in girls, however, these results did not reach statistical significance. Intake of vitamin D was lower than EAR in all of the studied children. Intakes of sodium (mg) and zinc (mg) were significantly higher in boys. Intakes of the remaining minerals were higher in boys, however, these findings did not reach statistical significance. Nutrient densities for all minerals, except for sodium, zinc and manganese, were higher in girls. All of the studied children had sodium intakes above UL.

CONCLUSIONS

Inadequate intakes of vitamin D, calcium and potassium in the studied 6-year-olds along with excessive sodium intake are the risk factors for developing osteoporosis and hypertension. To prevent these diseases in the studied children, educational programmes for both preschool staff and parents should be worked out and implemented.

The vitamin D analogue ED71 but Not 1,25(OH)2D3 targets HIF1α protein in osteoclasts

Although both an active form of the vitamin D metabolite, 1,25(OH)₂D₃, and the vitamin D analogue, ED71 have been used to treat osteoporosis, anti-bone resorbing activity is reportedly seen only in ED71- but not in 1,25(OH)₂D₃ -treated patients. In addition, how ED71 inhibits osteoclast activity in patients has not been fully characterized. Recently, HIF1α expression in osteoclasts was demonstrated to be required for development of post-menopausal osteoporosis. Here we show that ED71 but not 1,25(OH)₂D₃, suppress HIF1α protein expression in osteoclasts in vitro. We found that 1,25(OH)₂D₃ or ED71 function in osteoclasts requires the vitamin D receptor (VDR). ED71 was significantly less effective in inhibiting M-CSF and RANKL-stimulated osteoclastogenesis than was 1,25(OH)₂D₃in vitro. Downregulation of c-Fos protein and induction of Ifnβ mRNA in osteoclasts, both of which reportedly block osteoclastogenesis induced by 1,25(OH)₂D₃in vitro, were both significantly higher following treatment with 1,25(OH)₂D₃ than with ED71. Thus, suppression of HIF1α protein activity in osteoclasts in vitro, which is more efficiently achieved by ED71 rather than by 1,25(OH)₂D₃, could be a reliable read-out in either developing or screening reagents targeting osteoporosis.