Vitamin D Status and Its Consequences for Health in South Africa

In this review, reports were retrieved in which vitamin D status, as assessed by serum 25-hydroxyvitamin D [25(OH)D] levels, was measured in South African population groups with varied skin colours and ethnicities. Healthy children and adults were generally vitamin D-sufficient [25(OH)D level >50 nmol/L] but the majority of those aged above 65 years were deficient. A major role for exposure to solar ultraviolet radiation (UVR) in determining 25(OH)D levels was apparent, with the dietary contribution being minor. Limited data exist regarding the impact of recent changes in lifestyles on vitamin D status, such as urbanisation. With regard to disease susceptibility, 11 of 22 relevant publications indicated association between low 25(OH)D levels and disease, with deficiency most notably found in individuals with tuberculosis and HIV-1. Information on the relationship between vitamin D receptor variants and ethnicity, disease or treatment response in the South African population groups demonstrated complex interactions between genetics, epigenetics and the environment. Whether vitamin D plays an important role in protection against the range of diseases that currently constitute a large burden on the health services in South Africa requires further investigation. Only then can accurate advice be given about personal sun exposure or dietary vitamin D supplementation.Anna K. Coussens is supported by the Academy of Science of South Africa (Sydney Brenner Fellowship), Medical Research Council of South Africa-SHIP-02-2013; Robert J. Wilkinson by the Wellcome Trust Grants 084323 and 104893, Francis Crick Institute 10218, Medical Research Council of South Africa, National Research Foundation of South Africa 96841 and US National Institutes of Health U19AI111276; Liza Bornman by the Cancer Association of South Africa and the National Research Foundation of South Africa, Robyn M. Lucas by an Australian National Health and Medical Research Council Senior Research Fellowship 1107343; and Caradee Y. Wright by the Medical Research Council of South Africa and the National Research Foundation of South Africa