Vitamin D supplementation should not be given in same doses to everyone, researchers suggest. According to Dr. Murphy, Dr. Kittles, and Dr. Manson, African-Americans who live in areas with low sunlight is more likely to suffer from vitamin D deficiency than European-Americans living in the same environment. For instance, from 25 hydroxyvitamin D levels in 492 men, age 40 to 79 from Chicago and Illinois, researchers found that 93% of African-American and 69.7% of European-American men had deficiency in vitamin D.
Although vitamin D deficiency is mostly linked to low sunlight exposure, it was found that even those African-Americans who live in sunny areas also had lower levels of vitamin D. However, it is important to mention that vitamin D deficiency can be seen not only in African-American men, but also in people with lower incomes and higher body mass indexes.
Dr. Murphy associated this deficiency to higher levels of melanin pigment in the skin whose primary function is to prevent the absorption of the ultraviolet radiation, which leads to the reduction of vitamin D. Considering that more percentage of African-Americans are vitamin D deficient than European-Americans, Dr. Kittles insists that the general population should intake 1000 and 3000 IU a day. Since, vitamin D deficiency has been linked to many ailments, such as, breast cancer, prostate cancer, diabetes, rheumatoid arthritis, and multiple sclerosis, which researchers believe that the amount of intake should be regulated to reflect the differences between African-Americans and European-Americans.