Many factors can alter cutaneous vitamin D production such as
aging, skin pigmentation, sunscreen usage, time of the day, season
and latitude [5,7]. Latitude is an important determinant of vitamin
D status since the amount of UVB that penetrates the earth’s surface
decreases markedly with increasing latitude [8]. People residing far
from the equator are at an increased risk for vitamin D deficiency
due to decreased cutaneous synthesis of vitamin D [9]. People
residing near the equator should have lower prevalence of vitamin
D deficiency compared to people living at high latitudes. However,
according to the recent studies, vitamin D deficiency is also common
in these countries