Vitamin D status of 51–75-year-old Irish women: its determinants and impact on biochemical indices of bone turnover

Abstract

Objectives: To assess the vitamin D status of Irish postmenopausal women during wintertime, and to examine its relationship with serum parathyroid hormone (PTH) and biochemical markers of bone turnover. In addition, the determinants of wintertime serum 25-hydroxyvitamin D (25OH-D) levels in these women were investigated. Design: A cross-sectional observational study. Setting: Cork City, Ireland (528N). Subjects: Ninety-five apparently healthy, free-living postmenopausal women (aged 51 -75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism. Results: Forty-eight per cent and 7% of women had serum 25OH-D levels , 50 nmol l 21 and , 25 nmol l 21, respectively. 25OH-D levels in these women were positively associated with dietary calcium intake (P ¼ 0.0002) and use of vitamin Dcontaining supplements (P ¼ 0.031), and negatively associated with cigarette smoking (P ¼ 0.027) and body mass index (BMI) (P ¼ 0.030). Low serum 25OH-D levels (, 50 nmol l 21 ) were associated (P , 0.01) with elevated serum PTH levels. There were no significant differences in urinary pyridinium crosslinks or serum osteocalcin, biochemical indices of bone turnover, between subjects with serum 25OH-D levels above or below 50 nmol l 21 . Conclusion: A high proportion of Irish postmenopausal women had low vitamin D status (, 50 nmol l 21 ) during late wintertime, which appeared to lead to elevated levels of serum PTH but not of bone turnover markers. Use of regular low-dose supplemental vitamin D, meeting daily calcium recommendations, cessation of smoking and maintaining BMI in the normal range are important factors that could help maintain adequate vitamin D levels during wintertime in these women.

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

“…PINP is the degraded product of type I collagen in the extracellular matrix and circulating PINP mainly reflects the synthesis rate of type I collagen and the bone turnover rate. 34 Bone turnover increases with ageing and menopausal stage, which could partly be reflected in the values reported in this study, but there is also the additional impact of low vitamin D status and low habitual calcium intakes in our group of women increasing overall bone turnover. 21,34 In this study, PINP responded to fortified milk supplementation, decreasing by 7% at week 8 and by 12% at week 12.…”

The Effects of Regular Tanning Bed Use and Increased Vitamin D Status on Serum Markers of Bone Turnover in Healthy Adult Women

“…For example, studies of postmenopausal women without estrogen replacement therapy, show either no signifi cant relationship 10,31 or a signifi cant inverse relationship between serum 25(OH)D and osteocalcin 13 while investigations including subjects of premenopausal status have reported both a significant weak positive 31,38 and significant weak negative relationship. 39 Osteocalcin is a noncollageneous bonespecifi c protein produced by osteoblasts and incorported into the bone matix.…”

“…5 Moreover, the majority of published reports exploring vitamin D status and biochemical markers of bone formation are limited to postmenopausal women and populations with compromised vitamin D status. [9][10][11][12][13] Circulating concentrations of 25-hydroxyvitamin D (25(OH)D), the standard measurement of vitamin D status, are typically higher in individuals with increased exposure to ultraviolet B (UVB) radiation due to the cutaneous production of vitamin D from its precursor, 7-dehydrocholesterol. [14][15][16] One investigation recently demonstrated that healthy individuals routinely exposed to artifi cial UVB light via tanning beds have significantly greater serum 25(OH)D concentrations and hip BMD z scores than those who do not.…”

Session 3: Joint Nutrition Society and Irish Nutrition and Dietetic Institute Symposium on ‘Nutrition and autoimmune disease’ Nutrition in Crohn's disease

“…The identification of vitamin D insufficiency is, of course, not isolated to CD. Indeed, numerous studies now suggest that hypovitaminosis D is widespread in adult normal populations (42,(46)(47)(48) . A large cohort study of British adults has documented hypovitaminosis D in 47% of participants in winter and spring and 15 % during summer and autumn.…”