Abstract
BackgroundLower circulating vitamin D 25-hydroxyvitamin D (25(OH)D) concentrations are associated with higher type 2 diabetes risk in adults, although causality remains uncertain. However, associations between 25(OH)D and type 2 diabetes risk markers in children have been little studied, particularly in ethnic minority populations. We examined whether 25(OH)D concentrations were associated with insulin resistance in children and whether lower 25(OH)D concentrations in South Asians and black African Caribbeans could contribute to their higher insulin resistance.MethodsCross-sectional study of 4650 UK primary school children aged 9–10 years of predominantly South Asian, black African Caribbean and white European ethnicity. Children had fasting blood measurements of circulating 25(OH)D metabolite concentrations, insulin and glucose.ResultsLower 25(OH)D concentrations were observed in girls, South Asians and black African Caribbeans. In analyses adjusted for age, sex, month, ethnic group and school, circulating 25(OH)D was inversely associated with fasting insulin (−0.38%, 95% CI −0.49% to −0.27%), homoeostasis model assessment (HOMA) insulin resistance (−0.39%, 95% CI −0.50% to −0.28%) and fasting glucose (−0.03%, 95% CI −0.05% to –0.02%) per nmol/L increase in 25(OH)D; associations did not differ between ethnic groups. Ethnic differences in fasting insulin and HOMA insulin resistance (higher among South Asian and black African Caribbeans) were reduced by >40% after adjustment for circulating 25(OH)D concentrations.ConclusionCirculating vitamin D was inversely associated with insulin resistance in all ethnic groups; higher insulin resistance in South Asian and black African children were partly explained by their lower vitamin D levels. Whether vitamin D supplementation can reduce emerging type 2 diabetes risk needs further evaluation.
Funder
Bupa Foundation
National Institute for Health Research Applied Research Collaboration South London
Wellcome Trust
National Prevention Research Initiative
Subject
Public Health, Environmental and Occupational Health,Epidemiology
Reference45 articles.
1. Overview of general physiologic features and functions of vitamin D
2. National Institute for Health and Care Excellence (NICE) . Vitamin D deficiency in children. NICE Clinical Knowledge Summaries (CKS); 2022.
3. Scientific advisory committee on nutrition (SACN) vitamin D and health report. Public Health England; 2016.
4. Is a vitamin D fortification strategy needed?;Buttriss;Nutr Bull,2020
5. Public Health England (PHE) and Food Standards Agency (FSA) . National diet and nutrition survey. Results from years 7-8 (combined) of the rolling programme (2014/15 to 2015/16). 2018.