Annals of internal medicine
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Circulating concentrations of 25-hydroxyvitamin D [25-(OH)D] are used to define vitamin D deficiency. Current clinical 25-(OH)D targets based on associations with intermediate markers of bone metabolism may not reflect optimal levels for other chronic diseases and do not account for known seasonal variation in 25-(OH)D concentration. ⋯ National Institutes of Health.
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Timing of initiation of screening for breast cancer is controversial in the United States. ⋯ National Cancer Institute.