Calcium and vitamin D supplementation and cognitive impairment in the women's health initiative.
Study Goal
To examine the effects of calcium combined with vitamin D on cognitive outcomes in elderly women.
Results Summary
The study found no significant differences in incident dementia, mild cognitive impairment, or cognitive function between the treatment (calcium + vitamin D) and placebo groups.
Population
Elderly women aged 65 and older without probable dementia at baseline.
Effective Dosage
1,000 mg of calcium carbonate combined with 400 IU of vitamin D3 daily.
Duration
Mean follow-up of 7.8 years.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) | no change | incident dementia | women aged 65 and older without probable dementia at baseline | hazard ratio (HR) = 1.11, 95% confidence interval (CI) = 0.71-1.74, P = .64 | no significant differences | #1 |
1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) | no change | incident mild cognitive impairment (MCI) | women aged 65 and older without probable dementia at baseline | hazard ratio (HR) = 0.95, 95% confidence interval (CI) = 0.72-1.25, P = .72 | no significant differences | #2 |
1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) | no change | global cognitive function | women aged 65 and older without probable dementia at baseline | - | no significant differences | #3 |
1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) | no change | domain-specific cognitive function | women aged 65 and older without probable dementia at baseline | - | no significant differences | #4 |
1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) | no change | incident cognitive impairment | women aged 65 and older without probable dementia at baseline | - | no association | #5 |
OBJECTIVES: To examine the effects of vitamin D and calcium on cognitive outcomes in elderly women. DESIGN: Post hoc analysis of a randomized double-blind placebo-controlled trial. SETTING: Forty Women's Health Initiative (WHI) clinical centers across the United States. PARTICIPANTS: Four thousand one hundred forty-three women aged 65 and older without probable dementia at baseline who participated in the WHI Calcium and Vitamin D Trial and the WHI Memory Study. INTERVENTION: Two thousand thirty-four women were randomized to receive 1,000 mg of calcium carbonate combined with 400 IU of vitamin D(3) (treatment) and 2,109 to placebo. MEASUREMENTS: Primary: classifications of probable dementia or mild cognitive impairment (MCI) based on a four-phase protocol that included central adjudication. Secondary: global cognitive function and individual cognitive subtests. RESULTS: Mean age of participants was 71. During a mean follow-up of 7.8 years, 39 participants in the treatment group and 37 in the placebo group developed incident dementia (hazard ratio (HR) = 1.11, 95% confidence interval (CI) = 0.71-1.74, P = .64). Likewise, 98 treatment participants and 108 placebo participants developed incident MCI (HR = 0.95, 95% CI = 0.72-1.25, P = .72). There were no significant differences in incident dementia or MCI or in global or domain-specific cognitive function between groups. CONCLUSION: There was no association between treatment assignment and incident cognitive impairment. Further studies are needed to investigate the effects of vitamin D and calcium separately, on men, in other age and ethnic groups, and with other doses.