Medical researchers say Americans spend an estimated $31 billion each year on vitamins, but a massive new analysis again questions the benefit of most supplements to improve heart health or lengthen life.
In July, Johns Hopkins Medicine published findings from 277 clinical trials using 24 different interventions. It included data gathered on nearly 1 million research participants worldwide.
Although researchers found that most of the supplements or diets weren’t associated with any harm, the review showed possible health benefits only from a low-salt diet, omega-3 fatty acid supplements and possibly folic acid supplements for some people.
The analysis also found that supplements combining calcium and vitamin D might in fact be linked to a slightly increased stroke risk.
“The panacea or magic bullet that people keep searching for in dietary supplements isn’t there,” said Dr. Erin D. Michos, senior author of the study, in a news release. Michos, a study co-author, is an associate director of medicine in cardiology at the Johns Hopkins University School of Medicine.
“People should focus on getting their nutrients from a heart-healthy diet because the data increasingly show that the majority of healthy adults don’t need to take supplements.”
Surveys by the Centers for Disease Control and Prevention indicate 52% of Americans take a least one vitamin or other dietary or nutritional supplement daily. Past research – including this Johns Hopkins analysis – has failed to prove significant health benefits from most of them.
A Spokane professor has noticed a difference in supplements available now, in terms of how much is packed into a pill. Megadoses are the norm, argued John White, chairman of the pharmacotherapy department at Washington State University Spokane. The unit is part of the College of Pharmacy and Pharmaceutical Sciences.
“In the initial years when vitamins were becoming popular, most everybody went by RDAs (recommended daily allowances), and then supplements contained lower quantities of most of the vitamins,” White said.
“Over time, we’ve developed into a situation where a lot of supplements are megadose vitamins. It’s sort of the philosophy that too much of everything is just enough.”
Richard League, owner of Mother’s Cupboard Nutrition in Spokane, said he questions the point of such research because multivitamins are meant to fill in nutritional gaps, not make sweeping health claims.
“If this study is saying well, if you take a multivitamin, it’s not going to protect you from heart disease, cancer or dementia, then I would say ‘No, but I don’t think anyone says that’s going to happen.’ We don’t tell anyone that taking a multivitamin is going to protect them against any of those diseases because it’s not.
“A multivitamin is just there to fill in the gaps of your nutrition if you don’t get what you need in your food, and then you can make sure that you’ve got all your nutrients from taking a multivitamin.”
While some researchers question the money spent on vitamins, League counters that people should look at what goes into most grocery carts.
“If a person goes to a grocery store and buys good quality produce – maybe organic – and eats that, that is ideal, but most people don’t do that,” League said. “If you look at the grocery cart most people have, it’s not wholesome, organic fresh vegetables and fruits. It’s empty calories … chips and sweets.
“So are you going to say, ‘Oh, hey, you’re wasting your money here’? But if they want to buy vitamins that might help bridge the gap in nutrition, I don’t understand the big purpose of saying that’s a waste of money. Nobody is saying this is going to cure you or prevent heart disease.
“We have customers in our stores every day, and they demand these products and believe they work. I agree with them because I take them myself. I believe in them.”
White said another consideration is that some people have lab-tested vitamin deficiencies, so it’s recommended that they take certain supplements. Others might be deficient in one or two vitamins because of how they eat.
Low vitamin D levels are a consideration, especially in winters, among residents in such locations as the Northwest, Alaska and Canada, White said. It’s widely recommended that women in child-bearing years take a folic acid, while vegans are advised to take complex B vitamins.
But White also agreed science has yet to prove vitamins are as far-reaching for health as people hope. He said it begs another question: Should medical professionals recommend multivitamins to healthy individuals who eat well-balanced meals? Generally, people aren’t harmed by supplements, he added.
“I think if you look at everything on balance, what we’ve learned is there is no fountain of youth,” White said. “What everyone agrees on is that in individuals who take high-dose multivitamins, you do get very expensive yellow-colored urine.
“Based on this study and others, you’re probably not getting an inordinately great return on your investment unless you have particular conditions such as B-12 deficiency anemia.” The human body will absorb the vitamins and minerals it needs, and the rest are simply flushed out, he said.
There are two types of vitamins: water soluble and fat soluble. Fat soluble – A, D, E and K – are stored in fat tissue with rare toxicity if high levels are taken. Water-soluble vitamins – if unused in the body – go out into urine.
“If your body needs them when you take the supplement, it dissolves in your gastrointestinal tract, and they’re absorbed,” White said. “The fat solubles get stored in your fat, but you lose those, as well.”
‘A complicated landscape’
It’s also important to consider other individual differences, he said. Even within large studies of hundreds of thousands of people, some individuals likely benefited from vitamins, he added.
“It’s such a complicated landscape because each person brings their own genetics, their own environmental factors such as how much sunlight do they get, their own diet, and each person has their own needs,” White said.
“In trying to put all of these different pieces of the puzzle together, it seems to me pretty clear that the best approach is to try to consume a healthy, wide-ranging diet that’s low or with zero-processed food, with fresh components when possible, probably limiting sugar, and perhaps even some forms of fat.
“And maybe take a multivitamin, I don’t know, a couple of times a week.”
Results of the Johns Hopkins analysis were published in Annals of Internal Medicine. The researchers used data from 277 randomized clinical trials that evaluated 16 vitamins or other supplements and eight diets for their association with mortality or heart conditions, including coronary heart disease, stroke and heart attack.
The supplements reviewed included antioxidants, beta-carotene, vitamin B-complex, multivitamins, selenium, vitamin A, vitamin B3/niacin, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone, calcium and vitamin D together, folic acid, iron and omega-3 fatty acid (fish oil).
A variety of diets were reviewed, including a Mediterranean diet. The paper found little evidence that specific diets are beneficial, although reduced salt intake showed some benefit.
Members of the study group also have pointed to such heart-healthy habits as eating fresh fruits, vegetables and whole grains while exercising regularly and avoiding smoking.