Associations of vitamin D status with bone mineral density, bone turnover, bone loss and fracture risk in healthy postmenopausal women. The OFELY study
Introduction
Vitamin D status has for long been recognized as an important factor for bone health and its contribution has recently received increased attention [1], [2], [3], [4]. From a physiopathological point of view, vitamin D insufficiency, that corresponds to a smaller decrease of 25-hydroxyvitamin D (25-OH D) than vitamin D deficiency, may lead to secondary hyperparathyroidism resulting in higher bone remodeling, bone loss and ultimately increased skeletal fragility. Additionally, vitamin D insufficiency may increase postural instability through increased body sway and muscle weakness and reduced ability to counteract falls further increasing the risk of fracture [5]. However, most of studies which have supported these relationships have been performed in institutionalized subjects or older women of the community presenting with a high prevalence of vitamin D deficiency [6], [7], [8], [9]. Conversely, there are few prospective studies that have examined the relationships between mild vitamin D insufficiency and bone fragility in younger home-dwelling postmenopausal women from whom the majority of fractures arise. Supplementation trials with vitamin D3 in such population using bone loss or fracture incidence as an outcome have yielded conflicting results [3], [4], [10], [11], [12], [13]. Part of this controversy could be attributed to differences in starting levels of 25-OH D levels and/or to difference in the dose of vitamin D levels given as suggested by a recent meta-analysis [14].
The aim of our study was to investigate the associations between serum levels of 25-OH D, bone turnover, BMD and incidence of fracture in healthy postmenopausal women followed prospectively for a median of 11.2 years.
Section snippets
Participants
We investigated the postmenopausal women of the OFELY (“Os des Femmes de Lyon”) cohort, a prospective study of the determinants of bone loss which has been previously described in details [15]. The cohort of this study comprises 1039 Caucasian women 31–89 years of age, including 671 postmenopausal women, recruited between February 1992 and December 1993, from the regional section of a large health insurance company (Mutuelle Génerale de l'Education Nationale, Lyon, France) of the Rhône district
Relationships between serum 25-OH D and serum PTH
Serum 25-OH D levels decreased (r = − 0.19, p < 0.0001) whereas intact PTH increased (r = + 0.19, p < 0.001) with age. The relationships between serum 25-OH D levels and PTH were tested using different models and the best fitting curve was obtained with linear regression. As shown on Fig. 1, there was a moderate negative association between serum 25-OH D and serum intact PTH (r = − 0.15, p < 0.0001 after adjustment for age) (Fig. 1). Consequently in the subsequent analyses, cut-off values of 25-OH D were
Discussion
In this study, we analyzed the associations between serum 25-OH D levels, bone turnover, BMD, BMD loss and incidence of fracture in a population of healthy postmenopausal women from age 50 to 80 years. Although women with 25-OH D levels below 50 nmol/l or 30 nmol/l had a higher incidence of fracture than the other individuals, this difference disappeared after adjustment for age. No significant age-independent association could be detected between 25-OH D levels and BMD at the hip and forearm,
Acknowledgments
This study was partly supported by a contract INSERM/MSD Chibret (the OFELY study).
References (49)
- et al.
Redefining vitamin D insufficiency
Lancet
(1998) - et al.
Rates of bone loss in postmenopausal women randomly assigned to one of two dosage of vitamin D
Am. J. Clin. Nutr.
(1995) - et al.
Positive association between 25-hydroxyvitamin D levels and bone mineral density: a population-based study of younger and older adults
Am. J. Med.
(2004) - et al.
Low serum IGF-1 and occurrence of osteoporotic fractures in postmenopausal women
Lancet
(2000) - et al.
Fracture incidence and association with bone mineral density in elderly men and women: the Rooterdam Study
Bone
(2004) - et al.
Estimates of optimal vitamin D status
Osteoporos. Int.
(2005) - et al.
Relationship between serum parathyroid hormone levels, vitamin D sufficiency and calcium intake
JAMA
(2005) Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium or vitamin D, RECORD): a randomized placebo-controlled trial
Lancet
(2005)- et al.
Calcium plus vitamin D and the risk of fracture
N. Engl. J. Med.
(2006) - et al.
Vitamin D and muscle function
Osteoporos. Int.
(2002)
Vitamin D3 and calcium to prevent hip fractures in the elderly women
N. Engl. J. Med.
Effect of calcium and cholecalciferol treatment for three years on hip fractures in elderly women
BMJ
Subclinical vitamin D deficiency in postmenopausal women with low vertebral bone mass
J. Clin. Endocrinol. Metab.
Vitamin D status and sex hormone binding globulin: determinants of bone turnover and bone mineral density in elderly women
J. Bone Miner. Res.
Effect of calcium and vitamin D supplementation on bone density in men and women 65 years of age or older
N. Engl. J. Med.
Effect of four monthly oral vitamin D3 (cholecalciferol) supplementation on fractures and mortality in men and women living in the community: randomised double blind controlled trial
BMJ
Vitamin D supplementation and fracture incidence in elderly persons. A randomized, placebo-controlled clinical trial
Ann. Intern. Med.
A randomized controlled trial of vitamin D supplementation on preventing postmenopausal bone loss and modifying bone metabolism using identical twin pairs
J. Bone Miner. Res.
Fracture prevention with vitamin D supplementation: a meta analysis of randomized controlled trials
JAMA
Biochemical markers of bone turnover, endogenous hormones and the risk of fracture in postmenopausal women: the Ofely Study
J. Bone Miner. Res.
Vertebral fracture assessment using a semi quantitative technique
J. Bone Miner. Res.
Independents predictors of all osteoporosis related fractures in healthy postmenopausal women. The OFELY study
Bone
An international comparison of serum 25 hydroxyvitamin D measurements
Osteoporos. Int.
Calciotropic hormones and bone markers in the elderly
J. Bone Miner. Res.
Cited by (159)
Decreased bone mineral density, Vitamin K and Vitamin D in ulcerative colitis patients
2021, Medicina Clinica PracticaThe optimal cut-off point of vitamin D for pregnancy outcomes using a generalized additive model
2021, Clinical NutritionVitamin D, Cholesterol, and DXA Value Relationship with Bimaxillary Cone Beam CT Values
2023, Journal of Clinical Medicine