Vitamin D Supplementation and Sunlight Exposure in Brazilian Women Living in Opposite Latitudes (The D-SOL Study)
Vitamin D Supplementation and Sunlight Exposure in Brazilian Women Living in Opposite Latitudes (The D-SOL Study)
NCT ID: NCT03318029 Phase: NA Status: COMPLETED Enrollment: 136 Completion: 2017-09-25
Conditions
Vitamin D Deficiency
Interventions
Vitamin D supplementation, Placebo
Summary
There is a consensus that vitamin D deficiency is a public health issue because of its implications in several diseases including, osteopenia, osteomalacia, heart disease, diabetes (type I and II), inflammatory diseases, multiple sclerosis and rheumatoid arthritis. Studies in sunny countries have shown that vitamin D deficiency is a common phenomenon, despite the abundance of sunlight in these places, which shows the influence of diet, skin pigmentation, cultural habits and also genetic factors on the metabolism of this vitamin. Thus, the study hypothesis is that vitamin D supplementation is required to obtain the optimal serum concentration in Brazilian people living both in Brazil and in the United Kingdom and that this response is dependent on the initial levels, being influenced by sunlight exposure, skin pigmentation, diet and polymorphisms of the vitamin D receptor gene. Two controlled, randomized, double-blind clinical trials were held (one in the UK and the other in Brazil) over a period of 12 weeks, with female subjects, Brazilian, aged 20 to 59 years. The women selected were divided into two groups: Placebo Group and Supplemented Group, the latter received vitamin D 600 IU. After the analysis of the effect of vitamin D supplementation compared to placebo, the investigators propose to analyse genome-wide transcriptomic expression in order to associate specific signal transduction and metabolic pathways to respective vitamin D responses. and a genetic risk score based on polymorphisms will be constructed. The 'systems level' approach will enable us to identify differences in gene expression and whether this explains why some individuals are 'good' responders or 'poor' responders to vitamin D supplementation. This is the first study that will examine two population groups of the same ethnic group and sex, living in different countries, with identical design studies. Our results first will determine how important supplementation and exposure to sunlight are fo
Primary Outcome
Change from baseline vitamin D status at 12 weeks of vitamin D supplementation