Vitamin D deficiency in Mongolian men aged 15-49 years.

We aimed to estimate the prevalence of vitamin D deficiency in Mongolian men aged from 15 to 49 years at the National level as part of the Fifth National Nutrition Survey in 2016. This was a cross-sectional survey, conducted between September and November in 21 aimags of 4 economic regions of the country, and also in Ulaanbaatar. Given the regional differences in lifestyle and nutritional status, the target populations were stratified into 5 strata based on their economic region and in Ulaanbaatar, with equal samples drawn from each stratum using a cluster-randomized sampling design. A representative sample of 30 clusters [villages] was randomly selected using Probability Proportional to Size [PPS] methodology in each of the 4 regions and in Ulaanbaatar for a total of 150 cluster units. The selection of survey participants differed for the three sampling regions. Household eligibility was based on having a child 0-59 months of age, living in the household which was randomly selected from each cluster for a total of 450 households in each region. Households with a child 0-59 months of age were selected from household lists available at the kheseg or bagh level. All men 15-49 years of age who resided in the selected households were also eligible to participate in the survey. Serum concentration of 25-hydroxyvitamin D [25(OH)D] were measured using an enzyme-linked fluorescence assay in 377 men aged 15-49 years. The overall mean serum level of 25(OH)D concentration was 22.26 ± 0.48 ng/mL (95 % CI 21.31-23.21). The mean serum 25(OH)D concentrations were 19.65 ± 0.32 ng/mL (95 % CI19.01-19.82), and 33.68 ± 0.49 ng/mL (95 % CI 32.72-34.64) in vitamin D deficient, and in vitamin D sufficient subjects, respectively. The prevalence of vitamin D deficiency was 83.5 % with no significant difference in the prevalence of vitamin D deficiency by age group, economic region, area, location, education, and wealth index quintile. The prevalence of men in this study who were overweight or obese was 48.8 % and 14.6 % respectively. Although no significant difference was found between vitamin D deficiency and obesity, vitamin D deficiency was higher among men aged 30-39 and 40-49 years old by age specific analyses. The men did not take vitamin D supplements, and there is currently no vitamin D food fortification in Mongolia. The findings of this survey showed that vitamin D deficiency in men is a public health problem in Mongolia. In conclusion, vitamin D deficiency are common in Mongolian men, which indicates the need for vitamin D screening and treatment, as well as for an increased use of vitamin D supplements and for implementing vitamin D food fortification programs.