Resolution of vitamin D insufficiency in osteopenic patients results in rapid recovery of bone mineral density

Vitamin D insufficiency is characterized biochemically by the presence of secondary hyperparathyroidism, which can contribute to bone loss in osteopenic patients. Over a 2-yr period of evaluation of 118 consecutive, free living patients with osteopenia or osteoporosis, we identified 18 subjects with depressed serum 25-hydroxyvitamin D (250HD; less than or equal to 14 ng/mL). Twelve of these subjects harbored a low 25OHD level and consented to undergo replacement with 50,000 IU vitamin D, twice weekly for 5 weeks. Five hundred thousand units of oral vitamin D, resulted in significant increases in 250HD (+24.3 +/- 16.9 ng/mL; P < 0.001) and the fasting urinary calcium/creatinine excretion ratio (+0.06 +/- 0.004; P = 0.01) and significant decreases in the serum concentration of PTH (-32.9 +/- 36.9 pg/mL; P < 0.001) and osteocalcin (-4.9 +/- 2.4 ng/mL; P < 0.001). Vitamin D repletion was associated with a significant 4-5% annualized increase in bone mineral density at both the lumbar spine (P < 0.001) and the femoral neck (P = 0.03), indicating that resolution of vitamin D insufficiency in a population of patients with low bone mass results in a rapid rebound increase in bone mineral density.