Vitamin D Status, Parathyroid Function, Bone Turnover, and BMD in Postmenopausal Women With Osteoporosis: Global Perspective

Abstract

Poor vitamin D status is common in the elderly and is associated with bone loss and fractures. The aim was to assess worldwide vitamin D status in postmenopausal women with osteoporosis according to latitude and economic status, in relation to parathyroid function, bone turnover markers, and BMD. The study was performed in 7441 postmenopausal women from 29 countries participating in a clinical trial on bazedoxifene (selective estrogen receptor modulator), with BMD T-score at the femoral neck or lumbar spine 22.5 or one to five mild or moderate vertebral fractures. Serum 25(OH)D, PTH, alkaline phosphatase (ALP), bone turnover markers osteocalcin (OC) and C-terminal cross-linked telopeptides of type I collagen (CTX), and BMD of the lumbar spine, total hip, femoral neck, and trochanter were measured. The mean serum 25(OH)D level was 61.2 ± 22.4 nM. The prevalence of 25(OH)D <25, 25-50, 50-75, and >75 nM was 5.9%, 29.4%, 43.5%, and 21.2%, respectively, in winter and 3.0%, 22.2%, 47.2%, and 27.5% in summer. Worldwide, a negative correlation between 25(OH)D and latitude was observed. With increasing 25(OH)D categories of <25, 25-50, 50-75, and >75 nM, mean PTH, OC, and CTX were decreasing (p < 0.001), whereas BMD of all sites was increasing (p < 0.001). A threshold in the positive relationship between 25(OH)D and different BMD parameters was visible at a 25(OH)D level of 50 nM. Our study showed a high prevalence of low 25(OH)D in postmenopausal women with osteoporosis worldwide. Along with latitude, affluence seems to be an important factor for serum 25(OH)D level, especially in Europe, where it is strongly correlated with latitude.

High-calcium, vitamin D fortified milk is effective in improving bone turnover markers and vitamin D status in healthy postmenopausal Chinese women

“…[21][22][23][24][25] A population study confirmed that raising vitamin D status step wise to sufficiency is accompanied by a significant increase in BMD at all sites. 26 In addition, there is a strong association between vitamin D deficiency and hip fractures, 27 which together with low calcium intakes indicate that older women in China may be at significant risk of fracture.…”

Vitamin D: the light side of sunshine

“…In mild-moderate vitamin D deficiency (412.5-o50 nmol/l), there is still sufficient substrate 25OHD to produce calcitriol in the kidney under the control of parathyroid hormone; hence, blood calcium and phosphate concentrations are normal and the bone is still normally mineralized, although parathyroid hormone levels are high, as are bone resorption and turnover markers (Holick, 2007). Bone mass, measured as bone mineral density or total body calcium content, is reduced with mild-moderate D-deficiency, both in younger people (Winzenberg et al, 2011) and older individuals (Kuchuk et al, 2009). Mild-moderate vitamin D deficiency also impairs coordinated muscle function (Bischoff-Ferrari et al, 2004;Wicherts et al, 2007).…”

Relationship of Focal Erosions, Bone Mineral Density, and Parathyroid Hormone in Rheumatoid Arthritis

“…Vitamin D deficiency and the associated secondary hyperparathyroidism are strong risk factors for osteoporosis 15 . Vitamin D deficiency has been found to be associated with a higher incidence of RA 16 as well as more active disease progression 17,18,19 , but this was not confirmed in other studies 20,21 .…”