Joan M Lappe, Dianne Travers-Gustafson, K Michael Davies, Robert R Recker, Robert P Heaney
Jun 1, 2007; 85:1586-1591
Cancer
June 1, 2007
February 7, 2012
Vitamin D insufficiency and health outcomes over 5 y in older women [Nutritional status, dietary intake, and body composition]
Background: Vitamin D insufficiency was shown to be associated with adverse musculoskeletal and nonskeletal outcomes in numerous observational studies. However, some studies did not control for confounding factors such as age or seasonal variation of 25-hydroxyvitamin D [25(OH)D].
Objective: We sought to determine the effect of vitamin D status on health outcomes.
Design: Healthy community-dwelling women (n = 1471) with a mean age of 74 y were followed in a 5-y trial of calcium supplementation. 25(OH)D was measured at baseline in all women. Skeletal and nonskeletal outcomes were evaluated according to seasonally adjusted vitamin D status at baseline.
Results: Fifty percent of women had a seasonally adjusted 25(OH)D concentration <50 nmol/L. These women were significantly older, heavier, and less physically active and had more comorbidities than women with a seasonally adjusted 25(OH)D concentration ≥50 nmol/L. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L had an increased incidence of stroke and cardiovascular events that did not persist after adjustment for between-group differences in age or comorbidities. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at increased risk of adverse consequences for any musculoskeletal outcome, including fracture, falls, bone density, or grip strength or any nonskeletal outcomes, including death, myocardial infarction, cancer, heart failure, diabetes, or adverse changes in blood pressure, weight, body composition, cholesterol, or glucose.
Conclusions: Vitamin D insufficiency is more common in older, frailer women. Community-dwelling older women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at risk of adverse outcomes over 5 y after control for comorbidities. Randomized placebo-controlled trials are needed to determine whether vitamin D supplementation in individuals with vitamin D insufficiency influences health outcomes. This trial was registered at www.anzctr.org.au as ACTRN 012605000242628.
Effects of calcium supplementation on lipids, blood pressure, and body composition in healthy older men: a randomized controlled trial [Vitamins, minerals, and phytochemicals]
Background: Calcium supplementation has been suggested to have beneficial effects on serum lipids, blood pressure, and body weight, but these possibilities have not been rigorously assessed in men.
Objective: This study evaluated the effect of calcium supplementation on the change in the ratio of HDL to LDL cholesterol (primary endpoint) and on changes in cholesterol fractions, triglycerides, blood pressure, and body composition (secondary endpoints).
Design: We carried out a randomized controlled trial of calcium supplementation in 323 generally healthy men over a period of 2 y. Subjects were randomly assigned to take placebo, 600 mg Ca/d, or 1200 mg Ca/d.
Results: There was no significant treatment effect on the ratio of HDL to LDL cholesterol (P = 0.47) nor on weight, fat mass, lean mass, triglycerides, or total, LDL, or HDL cholesterol (P > 0.28 for all). There were downward trends in systolic and diastolic blood pressures within the calcium-supplemented groups, but there were no significant treatment effects over the whole trial period (P > 0.60). In a post hoc analysis of those with baseline calcium intakes below the median value (785 mg/d), blood pressures showed borderline treatment effects (P = 0.05–0.06 for changes at 2 y in those who received 1200 mg Ca/d compared with placebo: systolic, –4.2 mm Hg; diastolic, –3.3 mm Hg). Low magnesium intake showed a similar interaction. No treatment effects on weight or body composition were found.
Conclusions: These data do not show significant effects of calcium supplementation on serum lipids or body composition. Calcium supplementation in those with low dietary intakes may benefit blood pressure control. This trial was registered with the Australian Clinical Trials Registry as ACTRN 012605000274673.
Effect of 5 y of calcium plus vitamin D supplementation on change in circulating lipids: results from the Women’s Health Initiative [Lipids]
Background: Dietary calcium and vitamin D intakes may be inversely associated with cardiovascular disease (CVD) risk, possibly because of their potential beneficial effects on circulating lipids. Clinical trials that have evaluated the effect of calcium supplementation on lipids are limited by a short follow-up, and data on vitamin D are scarce.
Objective: The objective was to evaluate the effect of a longer-term effect (over 5 y) of calcium and vitamin D (CaD) supplementation on changes in the concentrations of several lipids: LDL, HDL, non-HDL, total cholesterol, triglycerides, and lipoprotein(a) [Lp(a)].
Design: The study was conducted in 1259 postmenopausal women in the Calcium plus Vitamin D Trial (1 g elemental Ca as carbonate plus 400 IU vitamin D3/d compared with placebo) of the Women's Health Initiative. Analyses were conducted by intention-to-treat. Repeated measurements on lipids during follow-up were analyzed by linear mixed-effects models.
Results: Overall, the change in lipids was relatively small [≤5% except for Lp(a), which was 20–25%], and there was no significant difference in the mean change of any lipid variable between the active and placebo groups.
Conclusions: Our results indicate that CaD supplementation is not associated with lipid changes over 5 y. Existing and future CaD trials should consider evaluating this association for different doses of supplements. This study was registered at clinicaltrials.gov as NCT00000611.