Vitamin D is a lipid-soluble substance that has two forms, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). UV light is the main source of vitamin D that induces the conversion of 7-dehydrcholestrol to vitamin D in the skin. Food sources that contain a high amount of vitamin D are egg yolk, fish, and liver. Several studies revealed the wide prevalence of deficiency in Vit. D among the healthy population, in addition, different diseases have a relation with their inadequacy in the body. This review study summarized the results recorded by published articles in different regions in Iraq regarding vitamin D deficiency. The review concluded that there is a high prevalence of Vit. D deficiency among the population in different regions of Iraq.