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 PARISI; A CRISTÓFARI; C MAUTALEN

Minneapolis

Congreso; 25th Anual Meeting ASBMR; 2003

Recently Heaney et. al. (J Am Coll Nutr 2003 Apr ,22(2):142-6) reported that 25OHD serum levelsshould be above 34 ng/ml ( 86 nmol/l) for adequate calcium absorption and beneficial for the treatment ofosteoporosis. The dose of vitamin D required to rapidly reach adequate serum 25OHD levels (above34ng/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 sincemenopause, average BMI: 27.7±4.7 and average T score of lumbar spine/ femoral neck: -2.5. The patientswere 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, serumcrosslaps (sCTX), and 24 hours urine calcium (uCa) and urine creatinine were measured at baseline andafter 1, 2 and 3 months of treatment.Average baseline 25OHD levels for the whole population was 14.2 IU ng/ml. All individual values werebelow 34 ng/ml. No differences in baseline measurements were found among the three groups. Serum andurinary 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 valuesabove 34 ng/ml. Serum and urinary calcium values remained within normal range in all patients. Nosignificant 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 of25OHD in osteoporotic postmenopausal females appears to be much higher than the usual recommendeddose (800IU/day). Ten thousand units per day during 90 days was effective since 25OHD levels reached39 ng/ml ( range 28 to 55 ng/ml) and caused no side effects. Future studies should determine themaintenance dose, once the effective level has been achieved.OASIS