The initial analysis compared the treatment group (supplemented with 1000 mg/day of calcium and 400 IU/day of D3) to those taking placebo, and showed no benefit from supplementation (and this is what mass media picked up and reported). However, the problem was that compliance was not accounted for in the media reports. Of course, if a woman doesn't take the supplements, we can't logically expect there to be a benefit--whether or not she's in the experimental group is meaningless. If you dig deeper, some interesting results surface.
In this trial, more than 36,000 postmenopausal women aged 50-79 years were randomly assigned to treatment with a combination of 1000 mg daily of calcium (as carbonate) a 400 IU daily dose of vitamin D3, or placebo. These women received treatment for an average of 7 years, and follow-up occurred an average of 5 years after intervention, for a total follow-up of about 12 years.
While the initial analyses were neutral (in other words, the study showed no significant reduction in hip fracture among the treatment group), when the analyses were limited to those women who consumed at least 80% of their study pills (compared with the women who took at least 80% of their placebo pills), the results showed a statistically significant 29% reduction in the risk for hip fracture! Further, a significant 13% reduction in vertebral fracture was seen in addition to a significant improvement in bone mineral density, as measured by DXA (dual-energy X-ray absorptiometry).
The researchers also looked at cancer risk, and found a statistically significant 13% reduction in in situ breast cancer (but no effect on colon cancer, in contrast to most other studies showing reduce colorectal cancer risk).
For the cardiovascular measurement (such as heart disease, stroke, and total cardiovascular events), there was no evidence of benefit or risk. This is important to note given the controversy about whether calcium may increase the risk for cardiovascular events.
The overall findings appear to be favorable for calcium and vitamin D supplements compared with placebo, and show no real harm. The only thing that's been shown to harm women is not having a subscription to KnowGuff.com, so click HERE, quickly!
Source: Calcium plus vitamin D supplementation and health outcomes five years after active intervention ended: the Women's Health Initiative
- Billion-Dollar $upplements
- Another Study Proves Safety of Calcium Supplements
- Calcium Again Linked to Increased Heart Attack Risk
- Calcium Supplements Safe for Women
- Calcium Supplements are Safe According to New Study
- Calcium Supplements Reduce the Risk of Hyperparathyroidism
- Calcium with Vitamin D Reduces Premature Death Rate
- Calcium & D3 for Polycystic Ovaries and Kidney Disease
- Calcium with Phosphorus Reduces Intestinal Permeability
- Calcium Supplements Help Reduce the Risk of Endometrial Cancer
- Most Healthy People are Vitamin K Deficient
- K2 (as MK-7) Improves Bone Health in Latest Study
- Folic Acid for Bone Health