The majority of older adults, he says, can improve their diet to get needed nutrients.
"A lot of money is wasted in providing unnecessary supplements to millions of people who don't need them," says Donald B. McCormick, PhD, an Emory professor emeritus of biochemistry and the graduate program in nutrition and health sciences at Emory.
He challenges what he says is a widely held belief that the older people get, the more vitamins and mineral supplements they need.
The scientific backup for that doesn’t exist, he says. "We know too little to suggest there is a greater need in the elderly for most of these vitamins and minerals."
"A supplement does not cure the aging process," he says. And in some cases, supplements may do harm, he says. Expense is another factor.
His report, which reviews numerous studies of vitamins and mineral supplements, is published in Advances in Nutrition.
Duffy MacKay, ND, vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, an industry group representing dietary supplement makers, agrees that starting with a good diet is the best way to get needed nutrients.
But he says that is not always reality, especially for older adults who may have obstacles such as a reduced appetite.
Older-Adult Nutrient Needs
McCormick reviewed studies on dietary supplements in older adults published in the last 12 years.
He says that ''it is apparent that changes in requirements for the elderly do not suggest massive supplement use covering most micronutrients." He says minor diet changes can fill needs for nutrients, ''with supplements included only where there is evidence of serious limitation of intake."
He disagrees with a study suggesting that older adults should take two multivitamins a day. He found no evidence that older adults need more thiamin, riboflavin, or niacin than younger people. Some older adults may need more vitamin B6, B12, and folate, research suggests.
But vitamin C needs do not seem to change with age, he says, if an older adult does not smoke cigarettes.
McCormick also found no evidence that absorption or the body's use of vitamin E changes as people get older. He says there is a decrease in the way the skin makes vitamin D. So for some older adults, supplemental vitamin D may be needed. In some research, taking 800 to 1,000 IUs of vitamin D a day helped women who were past menopause.
Copper requirements don't seem to change with age, either, McCormick says.
Older adults often take in less chromium, but he says there is not evidence that there are any health consequences.
In his report, McCormick says supplements for cancer patients are not recommended. (His report was finalized before recent research linked the use of a daily multivitamin to decreased cancer risk modestly in male doctors age 50 and older.)
For older adults, McCormick has this advice: "If you are still eating fairly well, you are getting more micronutrients than you probably really need to function as well as you can."
Boosting nutrients above what can be gotten from a well-balanced diet won't necessarily lead to better health, he says.
At very high levels, some vitamins and minerals can be toxic, he says.
Perspectives: Vitamins, Supplements for Older Adults
''The adequate intake of vitamins in the elderly is a concern," MacKay of the Council for Responsible Nutrition says.
Changing the diet can be difficult for older people, he says. Living on fixed incomes may make fresh produce too costly.
Some older adults don't know how to cook. For others, ill-fitting dentures or a reduced appetite may make eating difficult.
"Where dietary changes are difficult, a dietary supplement can be a responsible, reasonable solution," he says.
The Academy of Nutrition and Dietetics says older adults should pay special attention to their intake of calcium, vitamin D, vitamin B-12, potassium, and fiber.
"It's always best to obtain your nutrients from food," says Andrea Giancoli, RD, MPH, a spokeswoman for The Academy of Nutrition and Dietetics. She reviewed the report for WebMD.
When she counsels older adults, Giancoli first figures out what nutrients are lacking in the diet. Often, it's vitamin D, calcium, and vitamin B12.
"I try to fix it with food," she says. For instance, she suggests someone with calcium deficits increase their dairy products.
"I don't think we should be recommending supplements blindly without assessing their food intake," she says.