Should you take multivitamins for your health?
Half of all Americans take a daily multivitamin or other type of vitamin supplement, according to a Gallup poll. U.S. vitamin sales total nearly $12 billion annually.
Just who takes all those vitamins? The survey found that there is a generational gap, with about a third of 18- to 29-year-olds saying they use vitamins, compared with nearly 70 percent of people 65 and older who take them.
But is there evidence that taking vitamins improves health and wards off chronic illnesses like heart disease or diabetes? Or can supplements actually be harmful?
“The medical community is pretty equally divided over the benefits of taking vitamins,” said Dr. Thomas Barringer , the co-medical director of Novant Health Heart & Vascular Institute in Charlotte. “There is no evidence that taking vitamins helps with cardiovascular health, cancer or Alzheimer’s disease.”
Barringer added that the scientific literature about the benefit of vitamins is “all over the map.” Most of this literature is from observational studies rather than clinical trials. The former type of study compares outcomes between vitamin users and nonusers, outcomes which may be due to differences other than vitamin usage. Only clinical trials can prove whether taking a multivitamin is the cause of better outcomes, the doctor said.
In an editorial published in the Annals of Internal Medicine , researchers wrote the following on this issue: “The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided.”
They went on add that some supplements, such as vitamins A and E, might actually be harmful to people who take them at high doses.
The American Academy of Family Physicians recommendations on vitamin use aren’t quite as black and white. They say that there is insufficient evidence to assess whether multivitamins help or cause harm with regard to cancer or cardiovascular disease. However, the academy recommends against taking beta carotene and vitamin E for the prevention of these diseases.
There are circumstances in which a person should talk to his or her doctor about taking vitamins, including:
- If you follow a vegan or vegetarian diet.
- If you are pregnant, trying to become pregnant or are breast-feeding.
- Dark-skinned and older people are more susceptible to vitamin D deficiency,” Barringer said.
- Taking vitamin D from a multivitamin or a supplement has an association with lower rates of colon cancer, as well as other chronic diseases such as osteoporosis, heart disease and multiple sclerosis. A current ongoing clinical trial is trying to determine if this association is due to cause-and-effect, Barringer said.
The Food and Drug Administration noted there are 13 vitamins that are essential to good health. These include vitamins A, C, D, E, K and B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate.)
People should be able obtain the vitamins they need from a proper diet. However, many Americans consume more calories than they need without obtaining necessary nutrients. That may result in deficiencies of calcium, potassium, fiber, magnesium, folic acid, iron, vitamins A and B-12, according to the FDA.
Barringer said patients who are concerned about getting adequate vitamins could take a standard multivitamin as a safety net. He recommended a daily multivitamin since they’re nearly all formulated in the same manner. “Stay away from mega-dose vitamins and super supplements,” Barringer said. “Excessive zinc and excessive vitamin D can be dangerous, for example.”
The federal government’s dietary guidelines offer the following advice:
Eat a balanced diet of nutrient-rich food that includes more fruits and vegetables. Consume whole grain foods rather than refined grains. Include in your diet lean protein such as fish and poultry.
Eat foods that are high in fiber, calcium and vitamin D. These nutrients can be found in vegetables, fruit, milk and whole grains.
Women of childbearing age or who are breast-feeding may need additional folic acid and iron. Your provider may recommend a supplement. Barringer said that grain products have been fortified with folate since 1998 and many women may not need additional folic acid.
People age 50 and older may require a B-12 vitamin supplement. “Absorption of B-12 becomes a problem as people age so an older person needs to have their level of B-12 measured,” Barringer said.
What’s the bottom line? “Eat a healthy diet,” Barringer said. “Fruits and vegetable are high in antioxidants, and multivitamins are not a substitute.”