Vitamin A and its dervatives effect on bone mineral density, a systematic review.

Abstract

Background:Even though vitamin A (Vit A) is one of the essential vitamins required for bone growth and development, it is still uncertain whether its effect on bone mineral density (BMD) is beneficial or harmful.Aim:To assess Vit A’s effect and its derivatives on BMD and the risk of developing osteoporosis.Data sources:PubMed, Cochrane Library, Science Direct, Embase, and Google Scholar were searched in February 2019 and updated in November 2020.Methods:Conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.Results:A total of 13 studies were included in this report out of 9,124 citations. Five of them were cross-sectional studies, and nine were cohort studies. Three out of five cross-sectional studies showed an increase in BMD, while two showed a decrease in BMD. Four out of eight cohort studies found an increase in BMD; two studies found no association between vitamin A level and BMD; one showed an inverse U-shape association of vitamin A with BMD, suggesting that both the increase or decrease levels of vitamin A affect BMD, while only one study showed a decrease in BMD.Conclusion:Although most of the included studies showed a favorable effect of Vit A on BMD, Vit A’s role or its derivatives on BMD change remains unclear.