WASHINGTON -- More than half of North American women receiving treatment for osteoporosis have suboptimal serum vitamin D levels, Anne E. de Papp, M.D., and her associates reported in a poster at the annual meeting of the American Association of Clinical Endocrinologists.
Inadequate vitamin D concentrations can lead to alterations in calcium and phosphate homeostasis, secondary hypoparathyroidism, bone loss, osteoporosis, and an increased risk of fractures.
Yet, data from a cross-sectional study of 1,536 postmenopausal women at 61 North American sites suggest the problem is often overlooked in osteoporosis patients, said Dr. de Papp, of Merck & Co. Inc., West Point, Pa., and her associates.
"We advocate the use of vitamin D supplementation and patient counseling regarding the importance of vitamin D in all women with osteoporosis," they said in the poster.
The patients had a mean age of 71 years (range, 47-103 years) and a mean body mass index (BMI) of 26.4 kg/[m.sup.2]. A total of 92% were Caucasian and 35% resided at latitude greater than or equal to 42[degrees]N (Boston), while 24% lived below 35[degrees]N (Memphis). All had been taking medication to treat or prevent osteoporosis for at least 3 months. The medications used included alendronate, calcitonin, etidronate, raloxifene, risedronate, and teriparatide.
Vitamin D supplementation at 400 IU / day or more was reported by 59.5%. The rest were taking less. The mean serum level of the active vitamin D metabolite 25-hydroxyvitamin D was 30.4 ng/ mL. Most (52%) had levels below 30 ng/mL, the minimum to maintain optimal serum parathyroid hormone levels (Osteoporos Int. 1997;7:439-43), while 36% had 25-hydroxyvitamin D levels below 25 ng/ mL, and 18% were below 20 ng/mL. Suboptimal 25-hydroxy vitamin D levels were found in 63% taking less than 400 IU / day of vitamin D, and in 45% of those receiving 400 IU or more per day.
Risk factors include having less than a 12th-grade education, lack of exercise, concomitant medication use, BMI of 30 or higher, nonwhite race, and age over 80 years.
The study was funded by Merck.
BY MIRIAM E. TUCKER
COPYRIGHT 2005 International Medical News Group
COPYRIGHT 2005 Gale Group