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Effect of winter oral vitamin D3 supplementation on cardiovascular risk factors in elderly adults
1Clinical Gerontology Unit, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, UK.
Insights
Vitamin D supplementation did not alter blood pressure or cholesterol levels in older adults during winter. This suggests that vitamin D deficiency is unlikely to cause the seasonal rise in cardiovascular disease risk factors.
Area of Science:
- Endocrinology
- Cardiovascular Medicine
- Nutritional Science
Background:
- Winter is associated with increased cardiovascular disease mortality.
- Vitamin D deficiency is common in winter and may influence cardiovascular health.
- The relationship between vitamin D levels and cardiovascular risk factors during winter requires investigation.
Purpose of the Study:
- To investigate the potential role of vitamin D deficiency in the winter increase of cardiovascular disease mortality.
- To test the effect of vitamin D supplementation on blood pressure and other cardiovascular risk factors during winter.
Main Methods:
- A randomized, double-blind, placebo-controlled trial was conducted.
- Participants (mean age 70 years) received a single oral dose of vitamin D (cholecalciferol) or a placebo.
- Follow-up assessments were conducted after 5 weeks.
Main Results:
- Vitamin D supplementation effectively increased serum 25-hydroxyvitamin D levels and decreased parathyroid hormone.
- No significant differences were observed in the mean change of systolic or diastolic blood pressure between the vitamin D and placebo groups.
- Serum cholesterol levels also showed no significant difference between the groups, but radial pulse significantly decreased in the vitamin D group.
Conclusions:
- Vitamin D supplementation did not impact blood pressure or serum cholesterol levels in this winter study.
- The findings suggest that decreased vitamin D levels are not the cause of the winter increase in blood pressure and cholesterol.
- Further research may be needed to explore other potential factors influencing seasonal cardiovascular changes.
Objective:
A possible role for vitamin D deficiency in contributing to the winter increase in cardiovascular disease mortality was investigated by testing the effect of vitamin D supplementation on blood pressure and other cardiovascular risk factors during winter.
Design:
Randomised double-blind trial of vitamin D supplementation in winter.
Subjects:
Men and women, mean age 70 years (range 63-76) recruited from general practitioner age-sex registers in Cambridge (UK).
Intervention:
95 people received a single oral dose of 2.5 mg cholecalciferol and 94 received the placebo at baseline interviews during December 1991. Follow-up assessment was 5 weeks later during January 1992.
Results:
Comparing follow-up with baseline assessment, serum 25-hydroxyvitamin D increased in the treated group and decreased slightly in the placebo group [mean (s.d.) change: 7.2 (+/- 3.8) vs -1.4 (+/- 1.1) ng/ml, P = 0.0001]; while parathyroid hormone decreased in the treated, and increased in the placebo, group [-0.27 (+/- 0.78) vs 0.13 (+/- 0.75) pmol/l, P = 0.0004]. However, the mean change in blood pressure was similar in both groups: systolic -5 (+/- 13) vs -5 (+/- 16) mmHg, P = 0.81; diastolic -1 (+/- 9) vs -1 (+/- 9), P = 0.92; as was the mean change in serum cholesterol [-0.07 (+/- 0.52) vs -0.05 (+/- 0.60) mmol/l, P = 0.81]. In contrast, the mean change in radial pulse was significantly decreased in the treated group compared with placebo [-2 (+/- 9) vs 1 (+/- 7) beats per min, P = 0.030].
Conclusions:
The failure of vitamin D supplementation to change blood pressure or serum cholesterol suggests that the winter increase in these factors is not caused by decreased vitamin D levels.