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
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.