25OHD levels ≥20 ng/ml are needed for a better muscle function and strength. Assessing vitamin D nutritional status in adults aged ≥ 65 years would allow correcting hypovitaminosis D and improve muscle function and strength.

Objective: Assessment of the effectiveness and safety of high daily 125 mg (5000 IU) or 250 mg (10 000IU) doses of vitamin D 2 during 3 months, in rapidly obtaining adequate 25 hydroxyvitamin D (25OHD) levels. Design: Longitudinal study. Subjects: Postmenopausal osteopenic/osteoporotic women (n ¼ 38) were studied during winter and spring. Median age (25-75th percentile) was 61.5 (57.00-66.25) years, and mean bone mineral density (BMD) was 0.902 (0.800-1.042)g/cm 2 . Subjects were randomly divided into three groups: control group (n ¼ 13): no vitamin D 2 , 125 mg/day (n ¼ 13) and 250 mg/day (n ¼ 12) of vitamin D 2 groups, all receiving 500 mg calcium/day. Serum calcium, phosphate, bone alkaline phosphatase (BAP), C-telopeptide (CTX), 25OHD, mid-molecule parathyroid hormone (mmPTH), daily urinary calcium and creatinine excretion were determined at baseline and monthly. Results: For all subjects (n ¼ 38), the median baseline 25 hydroxyvitamin D (25OHD) level was 36.25 (27.5-48.12) nmol/l. After 3 months, 8% of the patients in the control group, 50% in the 125 mg/day group and 75% in the 250 mg/day group had 25OHD values above 85 nmol/l (34 ng/ml). Considering both vitamin D 2 groups together, mmPTH and BAP levels diminished significantly after 3 months (Po0.02), unlike those of CTX. Serum calcium remained within normal range during the follow-up. Conclusions: The oral dose of vitamin D 2 required to rapidly achieve adequate levels of 25OHD is seemingly much higher than the usual recommended vitamin D 3 dose (20 mg/day). During 3 months, 250 mg/day of vitamin D 2 most effectively raised 25OHD levels to 85 nmol/l in 75% of the postmenopausal osteopenic/osteoporotic women treated.

D2 and D3 were equally effective in elevating 25OHD levels after a loading dose. In the long term, D3 seems more appropriate for sustaining 25OHD, which could be relevant for classic and non-classic effects of vitamin D.

The present study was undertaken to examine the effect of melatonin (25 microg/mL of drinking water, about 500 microg/day) on a 10-wk long treatment of male rats with methylprednisolone (5 mg/kg s.c., 5 days/wk). Bone densitometry and mechanical properties, calcemia, phosphatemia and serum bone alkaline phosphatase activity and C-telopeptide fragments of collagen type I (CTX) were measured. Both melatonin and methylprednisolone decreased significantly body weight (BW) and the combination of both treatments resulted in the lowest BW values found. Consequently, all results were analyzed with BW as a covariate. Densitometrically, methylprednisolone augmented bone mineral content (BMC), bone area (BA) and bone mineral density (BMD) in the entire skeleton, BMC in cortical bone, and BMC and BMD in trabecular bone. Melatonin increased BMC and BA in whole skeleton and BMC and BMD in trabecular bone. For BMC and BA of whole skeleton, BMC of cortical bone, and BMC and BMD of trabecular bone, the combination of glucocorticoids and melatonin resulted in the highest values observed. Femoral weight of rats receiving methylprednisolone or melatonin increased significantly and both treatments summated to achieve the greatest effect. In femoral biomechanical testing, methylprednisolone augmented ultimate load and work to failure significantly. Rats receiving the combined treatment of methylprednisolone and melatonin showed the highest values of work to failure. The circulating levels of CTX, an index of bone resorption, decreased after methylprednisolone or melatonin, both treatments summating to achieve the lowest CTX values found. Serum calcium increased after methylprednisolone and serum phosphorus decreased after treatment with methylprednisolone or melatonin while serum bone alkaline phosphatase levels remained unchanged. The results are compatible with the view that low doses of methylprednisolone or melatonin decrease bone resorption and have a bone-protecting effect.