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- Melhus, Håkan, et al.
(author)
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Plasma 25-Hydroxyvitamin D Levels and Fracture Risk in a Community-Based Cohort of Elderly Men in Sweden
- 2010
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 95:6, s. 2637-2645
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Journal article (peer-reviewed)abstract
- Context: Blood levels of 25-hydroxyvitamin D [25(OH)D] is the generally accepted indicator of vitamin D status, but no universal reference level has been reached. Objective: The objective of the study was to determine the threshold at which low plasma 25(OH)D levels are associated with fractures in elderly men and clarify the importance of low levels on total fracture burden. Design and Participants: In the Uppsala Longitudinal Study of Adult Men, a population-based cohort (mean age, 71 yr, n = 1194), we examined the relationship between 25(OH)D and risk for fracture. Plasma 25(OH)D levels were measured with high-pressure liquid chromatography-mass spectrometry. Setting: The study was conducted in the municipality of Uppsala in Sweden, a country with a high fracture incidence. Main Outcome Measure: Time to fracture was measured. Results: During follow-up (median 11 yr), 309 of the participants (26%) sustained a fracture. 25(OH)D levels below 40 nmol/liter, which corresponded to the fifth percentile of 25(OH)D, were associated with a modestly increased risk for fracture, multivariable-adjusted hazard ratio 1.65 (95% confidence interval 1.09-2.49). No risk difference was detected above this level. Approximately 3% of the fractures were attributable to low 25(OH)D levels in this population. Conclusions: Vitamin D insufficiency is not a major cause of fractures in community-dwelling elderly men in Sweden. Despite the fact that cutaneous synthesis of previtamin D during the winter season is undetectable at this northern latitude of 60 degrees , only one in 20 had 25(OH)D levels below 40 nmol/liter, the threshold at which the risk for fracture started to increase. Genetic adaptations to limited UV light may be an explanation for our findings.
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| 2. |
- Snellman, Greta, et al.
(author)
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Long-Term Dietary Vitamin D Intake and Risk of Fracture and Osteoporosis : A Longitudinal Cohort Study of Swedish Middle-aged and Elderly Women
- 2014
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 99:3, s. 781-790
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Journal article (peer-reviewed)abstract
- Context: The importance of dietary vitamin D for osteoporotic fracture prevention is uncertain. Objective: Our objective was to investigate associations between dietary vitamin D intake with risk of fracture and osteoporosis. Design and Participants: In the population-based Swedish Mammography Cohort (including 61 433 women followed for 19 years), diet was assessed by repeated food frequency questionnaires. Setting: The study was conducted in 2 municipalities in central Sweden. Main Outcome Measure: Incident fractures were identified from registry data. In a subcohort (n = 5022), bone mineral density was determined by dual-energy x-ray absorptiometry and serum 25-hydroxyvitamin D was measured using HPLC-tandem mass spectrometry. Results: A total of 14 738 women experienced any type of first fracture during follow-up, and 3871 had a hip fracture. Multivariable-adjusted hazard ratio (HR) for any first fracture was 0.96 (95% confidence interval, 0.92-1.01) for the lowest (mean, 3.1 mu g/d) and 1.02 (0.96-1.07) for the highest (mean, 6.9 mu g/d) quintile compared with the third quintile of vitamin D intake. The corresponding HR for a first hip fracture was 1.02 (0.96-1.08) for the lowest and 1.14 (1.03-1.26) for the highest quintile. Intakes >10 mu g/d, compared with <5 mu g/d, conferred an HR of 1.02 (0.92-1.13) for any fracture and an HR of 1.27 (1.03-1.57) for hip fracture. The intake of vitamin D did not affect the odds for osteoporosis, although higher levels were associated with higher bone mineral density (0.3%-2%, P < .0001). A positive association was observed between vitamin D intake and serum 25-hydroxyvitamin D. Conclusions: Dietary intakes of vitamin D seem of minor importance for the occurrence of fractures and osteoporosis in community-dwelling Swedish women.
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