10,000 IU of oral vitamin D per day are required to rapidly ( 3 months) reach adequate 25OHD in osteoporotic women.

MASTAGLIA SR, OLIVERI B, PARISI MS, CRISTÓFARI A, MAUTALEN C

Minneapolis, Minnesota, USA

Congreso; Twenty-Fifth Annual Meeting of the American Society for Bone and Mineral Research; 2003

The American Society for Bone and Mineral Research

10.000 IU of Oral Vitamin D Per Day Are Required to Rapidly (3 months) Reach Adequate 25OHD in Osteoporotic Women S. Mastaglia*, B. Oliveri, M. S. Parisi*, A. Cristófari*, C. Mautalen. Sección Osteopatías Médicas, Hospital de Clínicas, Universidad de Buenos Aires, Buenos Aires, Argentina. Recently Heaney et. al. (J Am Coll Nutr 2003 Apr ,22(2):142-6) reported that 25OHD serum levels should be above 34 ng/ml ( 86 nmol/l) for adequate calcium absorption and beneficial for the treatment of osteoporosis. The dose of vitamin D required to rapidly reach adequate serum 25OHD levels (above 34ng/ml) has not been established to date.Thirty four women living in Buenos Aires (34° S) aged 61.7± 5.5 years, with 15.7± 6.1 years since menopause, average BMI: 27.7±4.7 and average T score of lumbar spine/ femoral neck: -2.5. The patients were randomized to receive placebo (G1) or vitamin D in a daily oral doses of 5.000 IU(G2) or 10.000 IU (G3). All the subjects received calcium supplementation (500mg/day/tablets).Serum calcium, bone alkaline phosphatase (BALP), 25 hydroxivitamin D ( 25OHD), mm PTH, serum crosslaps (sCTX), and 24 hours urine calcium (uCa) and urine creatinine were measured at baseline and after 1, 2 and 3 months of treatment.Average baseline 25OHD levels for the whole population was 14.2 IU ng/ml. All individual values were below 34 ng/ml. No differences in baseline measurements were found among the three groups. Serum and urinary calcium were within normal range. The average increments of 25OHD are shown in the figure.At the end of 3 months 73% of group 3, 42% of group 2 and 0% of group 1 reached 25 OHD values above 34 ng/ml. Serum and urinary calcium values remained within normal range in all patients. No significant changes were observed in serum PTH, CTX or BAP.In the light of the present results, the oral dose of vitamin D required to rapidly achieve adequate levels of 25OHD in osteoporotic postmenopausal females appears to be much higher than the usual recommended dose (800IU/day). Ten thousand units per day during 90 days was effective since 25OHD levels reached 39 ng/ml ( range 28 to 55 ng/ml) and caused no side effects. Future studies should determine the maintenance dose, once the effective level has been achieved.