The exposure of the skin to solar ultraviolet B (UVB; 290–315 nm) radiation is considered as the most important sources of vitamin D. Vitamin D is rare in food. Among the vitamin D-rich food, oily fish are considered to be one of the best sources. The other factors that affect the cutaneous vitamin D synthesis are seasons, time of day, the length of the day, cloud cover, smog, skin melanin content, and sunscreen (1). UVB radiation does not penetrate glass, so exposure to sunlight indoors through a window does not produce vitamin D. Complete cloud cover reduces UV energy by 50%; shade (including that produced by severe pollution) reduces it by 60%. Individuals with restricted sun exposure need to include good sources of vitamin D in...