Does Oral vitamin D supplementation improve growth in school going children?

Oral vitamin D3 supplementation at a dosage of 14,000 IU per week for three years was successful in raising 25(OH)D concentrations in school-aged children with poor baseline vitamin D status, but it had no effect on growth, body composition, or pubertal development, says an article published in the Journal of American Medical Association.

Obesity, stunting, and early activation of the hypothalamic-pituitary-gonadal axis have all been linked separately to vitamin D insufficiency, which is defined as 25-hydroxyvitamin D [25(OH)D] 20 ng/mL, which is common in children living in temperate regions. There aren't enough phase 3 randomized clinical studies to look at how long-term vitamin D treatment affects body composition, growth, and pubertal development in school-aged kids with vitamin D insufficiency.

In order to ascertain if weekly oral vitamin D supplementation affects linear growth, body composition, or pubertal development in school-aged children living in an environment where vitamin D insufficiency is widely widespread, Davaasambuu Ganmaa and colleagues conducted this study.

In Ulaanbaatar, Mongolia, 18 grade schools participated in a double-blind, placebo-controlled, randomized clinical study from June 2016 to June 2019. Children who were enrolled in participating schools and were school-age (6 to 13 at baseline) were included. A positive QuantiFERON-TB Gold in-tube assay result, diseases or drugs linked to altered vitamin D metabolism, usage of vitamin D supplements, rickets symptoms, or plans to leave Ulaanbaatar within four years were among the exclusion criteria. A total of 9814 of the 11 475 kids who were asked to take part in the study received QFT testing, and 8851 of the children with negative findings were enrolled in the study. The placebo group had all but one participant finish follow-up and be included in the analysis. From November 2021 to February 2022, data were examined.

For a period of three years, participants in the study received either weekly oral doses of vitamin D3 (14 000 IU) or a placebo (n = 4433). Mean Tanner scores for pubertal development, mean percentage body fat, mean fat mass, and mean z scores for height for age, body mass index for age, and waist to height ratio.

The key findings of this study were:

1. The average age (SD) of the 8851 participants was 9.4 (1.6) years, with 4366 (49.3%) females and 8165 (92.2%) people of Khalkh ancestry.

2. The mean end-of-study 25(OH)D concentrations were 31.0 vs. 10.7 ng/mL among individuals randomly assigned to vitamin D vs. placebo, even though 8453 people overall (95.5%) had vitamin D deficiency at start.

3. However, neither overall nor within subgroups defined by baseline 25(OH)D concentration less than 10 ng/mL vs. 10 ng/mL or greater, estimated calcium intake less than 500 mg/d vs. 500 mg/d or greater, or male vs. female sex, vitamin D supplementation had an impact on mean height for age, body mass index for age, waist-to-height ratio, percentage body fat, fat mass, or fat-free mass.

Reference:

Ganmaa, D., Bromage, S., Khudyakov, P., Erdenenbaatar, S., Delgererekh, B., & Martineau, A. R. (2022). Influence of Vitamin D Supplementation on Growth, Body Composition, and Pubertal Development Among School-aged Children in an Area With a High Prevalence of Vitamin D Deficiency. In JAMA Pediatrics. American Medical Association (AMA). https://doi.org/10.1001/jamapediatrics.2022.4581