U.S. researchers suggest at-risk populations be screened for vitamin D deficiency and those found deficient should be treated with supplements. Dr. Michael F. Holick of the Boston University School of Medicine says the new clinical practice guideline recommends dietary intakes of vitamin D for children and adults at risk for vitamin D deficiency. \"Vitamin D deficiency is very common in all age groups and it is important that physicians and healthcare providers have the best evidence-based recommendations for evaluating, treating and preventing vitamin D deficiency in patients at highest risk,\" Holick, chairman of the task force that authored the clinical practice guideline, says in a statement. The guideline recommendations for dietary intake of vitamin D in patients at risk for vitamin D deficiency: Infants and children ages 1 and younger require at least 400 International Units a day of vitamin D, with children age 1 and older require at least 600 IU/day. Adults ages 19-50 years require at least 600 IU/day of vitamin D to maximize bone health and muscle function, but at least 1,500-2,000 IU/day of vitamin D may be needed to maintain blood level of vitamin D above 30 ng/ml, the level recommended. Adults ages 50-70 years need at least 600 IU/day and adults age 70 and older require at 800 IU/day. At least 1,500-2,000 IU/day of vitamin D may be needed to maintain blood level of vitamin D above 30 ng/ml. The clinical practice guideline is scheduled to be published in the July issue of the Journal of Clinical Endocrinology & Metabolism.