Randomized trial of three doses of vitamin D to reduce deficiency in pregnant Mongolian women.

BACKGROUND: In winter in Mongolia, 80% of adults have 25-hydroxyvitamin D (25(OH)D) concentrations <25 nmol/l (<10 ng/ml) and 99% have <50 nmol/l (<20 ng/ml). The vitamin D dose to avert deficiency during pregnancy in this population is unknown. METHODS: We conducted a randomized, controlled, double-blind trial of daily 600, 2000, or 4000 IU vitamin D3 for pregnant women in Mongolia (Clinicaltrials.gov #NCT02395081). We examined 25(OH)D concentrations at baseline (12-16 weeks' gestation), 36-40 weeks' gestation and in umbilical cord blood, using enzyme linked fluorescent assay. Sample size was determined to detect 0.4 standard deviation differences in 25(OH)D concentrations with 80% power. FINDINGS: 119 pregnant women were assigned 600 IU, 121 assigned 2000 IU and 120 assigned 4000 IU from February 2015 through December 2016. Eighty-eight percent of participants took ≥80% of assigned supplements. At baseline, 25(OH)D concentrations were similar across arms; overall mean ±â€¯standard deviation concentration was 19 ±â€¯22 nmol/l; 91% were < 50 nmol/l. At 36-40 weeks, 25(OH)D concentrations increased to 46 ±â€¯21, 70 ±â€¯23, and 81 ±â€¯29 nmol/l for women assigned 600, 2000, and 4000 IU, respectively (p < 0.0001 across arms; p = 0.002 for 2000 vs. 4000 IU). Mean umbilical cord 25(OH)D concentrations differed by study arm (p < 0.0001 across arms; p < 0.0001 for 2000 vs. 4000 IU) and were proportional to maternal concentrations. There were no adverse events, including hypercalcemia, attributable to vitamin D supplementation. INTERPRETATION: Daily supplementation of 4000 IU during pregnancy is safe and achieved higher maternal and neonatal 25(OH)D concentrations than 2000 IU. Daily 600 IU supplements are insufficient to prevent vitamin D deficiency in Mongolia. FUND: Anonymous foundation and Brigham and Women's Hospital.

Randomized trial of vitamin D supplementation for winter-related atopic dermatitis in children.

BACKGROUND: Epidemiologic and preclinical data, and a small randomized trial in Boston, suggest that vitamin D supplementation may improve winter-related atopic dermatitis (AD). OBJECTIVE: To determine the effect of vitamin D supplementation on winter-related AD. METHODS: We performed a randomized, double-blind, placebo-controlled trial of Mongolian children with winter-related AD (clinicaltrials.gov identifier: NCT00879424). Baseline eligibility included age 2 to 17 years, AD score 10 to 72 using the Eczema Area and Severity Index (EASI), and winter-related AD (eg, history of AD worsening during the fall-to-winter transition). Subjects were enrolled in Ulaanbaatar during winter and randomly assigned to oral cholecalciferol (1000 IU/day) versus placebo for 1 month. All children and parents received emollient and patient education about AD and basic skin care. The main outcomes were changes in EASI score and in Investigator's Global Assessment. RESULTS: The 107 enrolled children had a mean age of 9 years (SD 5), and 59% were male. Their median age of AD onset was 3 months (interquartile range 2 months to 1 year) and mean EASI score at baseline 21 (SD 9). One-month follow-up data were available for 104 (97%) children. Compared with placebo, vitamin D supplementation for 1 month produced a clinically and statistically significant improvement in EASI score (adjusted mean change: -6.5 vs -3.3, respectively; P = .04). Moreover, change in Investigator's Global Assessment favored vitamin D over placebo (P = .03). There were no adverse effects in either group. CONCLUSION: Vitamin D supplementation improved winter-related AD among Mongolian children, a population likely to have vitamin D deficiency in winter.

Mean level of 25 hydroxy vitamin d in mongolian people aged 25-55 / Монголын Анагаах Ухаан

BackgroundHuman vitamin D status primarily depends on skin exposure to the ultraviolet B (UVB) spectrum of the sunlight.Despite the many days of sunshine in Mongolia, the northern latitute means that much of the UVB is filteredout as it passes through the atmosphere. Studies of Mongolian infants, schoolchildren, and pregnant womenreveal prevalent and profound vitamin D deficiency in the winter months in Mongolia. To date, there has notbeen a single study of the vitamin D levels of Mongolian men, and no studies of working age women outside ofUlaanbaatar. The goal of this study is to determine Vitamin D levels among Mongolian working age populationin different geographical areas, in different seasons, and in different work settings.MethodsThis cross-sectional study was conducted among 120 healthy adults, recruited by a multistage clustersampling method in Ulaanbaatar, South Gobi, and Bulgan. Each participant was tested for serum 25(OH)Dconcentrations, twice in winter and summer. Samples were measured by ELISA. The paired sampling (120summer samples/120 winter samples total 240 samples) frame allowed us to compare an individual’s winter25(OH)D levels to their own summer 25(OH)D levels, avoiding any confounding by differences betweenindividuals. A paired T-test (two sided) with unequal variances was used to test for differences in 25(OH)Dlevels among study groups.Results95% of all participants were Vitamin D deficient (<20 ng/ml) in winter, 24% deficient in summer (p < 0.001).The mean winter serum 25(OH)D levels were (±SD) 10.7±5.3 ng/ml, which were doubled in the summer to(±SD) 26.1±8.1 ng/ml. In all three regions, men and women had similar mean 25(OH)D levels. In Ulaanbaatar,office workers had higher winter 25(OH)D levels than urban outdoor workers. Surprisingly, office workersin the Gobi had higher 25(OH)D levels than nomads in both winter and summer. In Bulgan, there were nodifferences between office workers and nomads in any season.ConclusionWe observe that low vitamin D levels are more prevalent in our winter samples of healthy working age adults.The prevalence of vitamin D deficiency is very high amongst the adult population. These data suggest a needto increase vitamin D intake either through improved fortification and/or supplementation.