Vitamin D, 25-Hydroxy

An estimated 68% to 77% of patients have suboptimal (<30 ng/mL) levels of vitamin D. This important nutrient promotes skeletal health by enhancing the intestinal absorption of calcium and phosphorus. Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead to hypercalcemia