SUPPLEMENTS | What research shows really happens

GLUCOSAMINE AND CHONDROITIN SULFATE
The belief: Glucosamine and chondroitin sulfate relieve knee pain caused by osteoarthritis.
The findings: In a large federally sponsored clinical trial, the combo worked no better than placebo in relieving osteoarthritis pain for most of 1,583 participants. A small group with moderate to severe pain saw a modest benefit from glucosamine-chondroitin.
The caveats: Because the subgroup of those with moderate to severe pain was so small -- about 300 people -- more research needs to be done to confirm this finding.
The bottom line: A combination of glucosamine and chondroitin sulfate doesn't relieve knee pain for most people with osteoarthritis; it may yet be shown to help those with moderate to severe osteoarthritis of the knee.
CALCIUM AND VITAMIN D
The belief: Calcium and vitamin D supplements reduce the risk of bone thinning and hip fractures associated with osteoporosis.
The findings: Among more than 36,000 women ages 50 to 79, daily calcium and vitamin D supplements reduced bone thinning only slightly, had an unclear effect on hip fracture risk and didn't protect against other fractures. Women 60 and older who took the supplements saw a statistically significant reduction in hip fractures.
The caveats: Supplements increased the risk of kidney stones. For most women, the benefits outweigh this risk, say experts.
The bottom line: Women should get most required calcium and vitamin D through diet and sun exposure, say experts; supplements should be taken, if necessary.
B VITAMINS
The belief: B vitamins cut risk of heart attacks and strokes by reducing the level of homocysteine (an amino acid) in the blood.
The findings: Two large studies showed that while B vitamins did reduce homocysteine, they didn't reduce risk of heart attacks and strokes in people with heart disease or diabetes.
The caveats: Healthy people may derive more protective benefit from B vitamins, suggests a trade group for supplement makers.
The bottom line: B vitamins do not appear to lower the risk of heart attack and stroke.
MULTIVITAMINS
The belief: Multivitamins help ward off chronic diseases such as cancer and heart disease.
The findings: A federal panel found that there wasn't enough evidence to recommend for or against taking multivitamins.
The caveats: Some studies show benefits and others, risks, for the same vitamins. A few supplements did offer clear protection against some ailments -- such as folic acid to prevent some birth defects.
The bottom line: A healthy diet is a better source of vitamins and minerals than supplements. Interaction among nutrients in food may offer benefits that supplements can't match.
ECHINACEA
The belief: Echinacea, an herbal remedy, helps fight the common cold.
The findings: Taking echinacea extracts before or after exposure to the common cold virus did not affect the rates of infection or the severity of symptoms for 437 study participants randomly assigned to receive echinacea or a placebo.
The caveats: The authors acknowledge that other preparations of echinacea not tested in the study may have different biologic effects.
The bottom line: Echinacea does not appear to provide relief from the common cold.
Washington Post