CONCLUSIONS AND RECOMMENDATIONS
The woman described in the vignette is a healthy postmenopausal woman with slightly low bone mineral density and a 25-hydroxyvitamin D level of 21 ng per milliliter. Although the laboratory that performed the measurement, and many other laboratories, would label that level as insufficient, she is certainly not deficient in vitamin D. According to the Fracture Risk Assessment Tool (FRAX) developed by the World Health Organization, the probability that she will sustain a hip fracture over the next 10 years is less than 1%. Moreover, she is not at high risk for falls and is unlikely to have osteomalacia.48 Hence, for patients such as this one, I would recommend an exercise program and a total calcium intake of 1200 mg per day. There remains uncertainty about whether vitamin D supplementation is appropriate for her, and if so, what the dose should be, although the recent IOM guidelines recommend 600 IU daily for a postmenopausal woman who is not at high risk for fractures or falls and 800 IU daily for persons who have a very high risk of osteoporosis or who are older than 70 years of age. 14 I would explain that despite the recent focus in the media on the potential role of vitamin D in reducing the risk of various chronic diseases, this hypothesis requires testing in large, randomized, controlled trials, and vitamin D cannot currently be recommended for the purpose of reducing the risk of heart disease or cancer.