Vitamin D Deficiency in Brazil: Questions about Potential Causes and Clinical Characteristics*

Vitamin D is a micronutrient essential to various systems from the human body, and it is not restricted to the classical function of bone mineralization. Its synthesis is mainly related to ultraviolet B (UVB) radiation exposure. Although Brazil is a tropical country with high levels of UVB radiation, counter-intuitively, a large number of Brazilians present vitamin D deficiency, which is also a worldwide issue. This review aims to approach clinical features and explore potential causes for this apparent contradiction through questions that could explain vitamin D deficiency in the Brazilian population.