Summary:
Total 82 studies were included in which 12 studies represented vitamin D levels in healthy individuals (Table 1) and 70 studies (Table 2) in different conditions. It found that vitamin D deficiency is prevalent in all parts of the country and about 64.6% healthy subjects had vitamin D levels less than 30 ng/mL. Moreover, 70 studies showed its deficiency in some diseases such as musculoskeletal, bone and periodontal problems, nursing mothers and children, tuberculosis, diabetes, cardiovascular problems and some type of cancers.
Women were found more deficient than men due to the cultural norms and clothing style in this population. Some previous studies in different parts of the world also showed that cultural norms and dress style were associated with vitamin D deficiency in women (134-136).
Limited studies have been conducted to see the association of genetic variations with some diseases. The results of such studies could not establish any significant association with different diseases. This could be due to the small sample size with limited scope of the study.