Leitzen, Keith2009-05-062009-05-062009-05-06https://hdl.handle.net/11299/49792The information provided in this handout does not necessarily reflect the views of the University of Minnesota Medical School physicians and faculty. These materials are provided for informational purposes only and are in no way intended to take the place of the advice and recommendations of your personal health care provider. You use the information provided in these handouts at your own risk.Vitamin D is important for muscle and bone health. Vitamin D deficiency is associated with cortical bone loss, increased bone turnover, and increased parathyroid hormone levels, predisposing to osteoporosis. Vitamin D supplementation increases bone density in established deficiency. Historically, the main source of vitamin D was exposure to sunlight. However, changes in lifestyle and awareness of the hazards associated with sun exposure have changed this. Also, Sunscreen sun protection factor 15 (adequately applied) reduces previtamin D synthesis by >99%. At latitudes greater than 35 degrees (MN is at 40 and greater degrees), UVB energy is insufficient to produce vitamin D during the winter months,4 producing a ‘vitamin D winter’ of variable duration, centered on the winter solstice. During these times of no cutaneous vitamin D production, dietary intake of vitamin D and previous vitamin stores become important. Treating deficiency involves correcting the vitamin D deficit and ensuring continuing maintenance of vitamin D status.en-USVitamin DdeficiencyricketsosteomalaciacholecalciferolergocalciferolOther