Results:
Total 82 studies were included in which 12 studies showed vitamin levels less than 30 ng/mL in the healthy individuals (male and female) and 70 studies in different disease conditions. It found that 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.