Prevalence and Determinants of Vitamin D Deficiency in 1825 Cape Town Primary Schoolchildren: A Cross-Sectional Study

• Published in: Nutrients Vol. 14; no. 6; p. 1263
• Main Authors: Middelkoop, Keren, Walker, Neil, Stewart, Justine, Delport, Carmen, Jolliffe, David A, Nuttall, James, Coussens, Anna K, Naude, Celeste E, Tang, Jonathan C Y, Fraser, William D, Wilkinson, Robert J, Bekker, Linda-Gail, Martineau, Adrian R
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 16.03.2022; MDPI
• Subjects: 25-Hydroxyvitamin D; Age; Asthma; Body mass; Body mass index; Body size; Calciferol; Child; children; Children & youth; Confidence intervals; Consent; cross-sectional; Cross-Sectional Studies; Elementary schools; Ethics; Guardians; Humans; Hyperparathyroidism; Parathyroid; Parathyroid Hormone; Parents & parenting; Prevalence; Software; South Africa; South Africa - epidemiology; Statistical analysis; Tuberculosis; Vitamin D; Vitamin D Deficiency; Vitamin deficiency; South Africa; United States > US; Africa; cross-sectional; prevalence; South Africa; children; vitamin D
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu14061263

Vitamin D deficiency (25-hydroxyvitamin D[25(OH)D] <50 nmol/L) is common among adults in Cape Town, South Africa, but studies investigating vitamin D status of children in this setting are lacking. We conducted a cross-sectional study to determine the prevalence and determinants of vitamin D deficiency in 1825 Cape Town schoolchildren aged 6−11 years. Prevalence of vitamin D deficiency was 7.6% (95% Confidence Interval [CI] 6.5% to 8.9%). Determinants of vitamin D deficiency included month of sampling (adjusted odds ratio [aOR] for July−September vs. January−March 10.69, 95% CI 5.02 to 22.77; aOR for October−December vs. January−March 6.73, 95% CI 2.82 to 16.08), older age (aOR 1.25 per increasing year, 95% CI: 1.01−1.53) and higher body mass index (BMI; aOR 1.24 per unit increase in BMI-for-age Z-score, 95% CI: 1.03−1.49). In a subset of 370 participants in whom parathyroid hormone (PTH) concentrations were measured; these were inversely related to serum 25(OH)D concentrations (p < 0.001). However, no association between participants with hyperparathyroidism (PTH >6.9 pmol/L) and vitamin D deficiency was seen (p = 0.42). In conclusion, we report that season is the major determinant of vitamin D status among Cape Town primary schoolchildren, with prevalence of vitamin D deficiency ranging from 1.4% in January−March to 22.8% in July−September.