African-American men living in areas with low sunlight are up to 3 ½ times more likely to have Vitamin D deficiency than Caucasian men and should take high levels of Vitamin D supplements, according to a new study from Northwestern University Feinberg School of Medicine. “This study shows that the current one-size fits all recommendations for 600 International Units (IU) of Vitamin D don’t work,” said Adam Murphy, M.D., a clinical instructor in urology at Northwestern’s Feinberg School. “Skin color and sunlight exposure need to be considered for recommended daily allowances of Vitamin D.” Vitamin D deficiency causes brittle bones and has been linked to such diseases as prostate cancer, diabetes, rheumatoid arthritis and multiple sclerosis.