Myths abound about the efficacy of taking a daily multivitamin. The April 12 edition of the Wall St. Journal’s Health section featured two eminent professors of medicine and epidemiology squaring off regarding this issue. While no definitive conclusion was reached, their discussion may inform your decision. The most conclusive evidence quoted shows a small benefit that may be offset by the risks of thinking that a multivitamin can take the place of other healthy habits.
Dr. Meir Stampfer of Harvard Medical school believes that a multi-vitamin serves as a type of low-cost, and relatively low-risk nutritional insurance. He believes that the vast majority of Americans don’t reach optimal levels of vitamin and mineral values in their bloodstream, so a multivitamin is an inexpensive way to insure that this happens.
Many studies have shown that a large portion of Americans are deficient in two vitamins in particular; Vitamin D and vitamin B-12. It’s difficult to absorb Vitamin D from diet alone. The most effective way to produce vitamin D is to get at least 15 minutes of daily sunlight exposure to your face and arms (at a minimum) to receive the benefit. Inadequate levels of this vitamin can lead to reduced bone and muscle strength and increased risk of various cancers. Once again, this must be weighed against too much exposure to sunlight without protection, which can lead to skin cancer. Vitamin B-12 is another common deficiency in Americans. Many people over 65 have difficulty absorbing this vitamin from their diets, even if they have adequate intake, because they lack the stomach acid necessary to release B-12 from food that contains it. This is where supplements may be effective, as acid isn’t needed for B-12 absorption from pills. A lack of B-12 can contribute to nervous system disorders like neuropathy, causing pain, numbness and weakness in hands and feet.
This leads to a logical question- why not take just the supplements needed, instead of a multi-vitamin? For instance, if you suspect you have one of these deficiencies, it’s sensible to get a lab test to determine if a specific deficiency exists. Dr. Stampfer believes that taking a preventive approach that may cover all the bases is better than taking them after damage is done. He add that you may be obtaining other vitamins that are lacking like A and B-6, which are also commonly deficient.
Dr. Stampfer admits that definitive research on multivitamins is scarce, though the one major long-term study done on 14,641 physicians over 14 years did show an 8% reduction in cancer risk, but this may be due to a variety of factors. Many physicians maintain healthy lifestyles which include exercise and a nourishing diet , and it’s hard to separate confounding factors. He maintains that the safety and low cost of multi-vitamins offset the minor risks. The major issue Stampfer sees are that people may pay less attention to the lifestyle modifications that we know improve quality and longevity of life, such as exercise, a healthy diet, and avoidance of smoking and excessive alcohol intake.
Dr. Eliseo Guillar of Johns Hopkins University offers the flip side of multivitamin use. He maintains that there is sparse evidence of their efficacy, which was concluded from a broad review of data from many studies. He sees no consistent evidence of a beneficial effect on cardiovascular disease or cancer, or mortality on individuals who have no known nutritional deficiencies. Dr. Guillar says that a balanced diet is a much more effective way to absorb all the vitamins and minerals that we need. Although having a balanced diet is not always easy, multivitamins are not a panacea for this problem. As for the commonly seen deficiencies in Vitamin B-12 and Vitamin D, he believes that laboratory testing is the only sure way to know whether these deficiencies exist in an individual, and if you have one, you should take supplements to address the specific problem. If you believe that a multivitamin addresses the problem, you may delay getting to a clinician who can address the actual problem thoroughly, delaying proper treatment.
Guillar’s thesis is that energy, time and effort are better spent on encouraging and motivating people to eat a diet rich in vegetables, fruits, seeds, nuts, whole grains, legumes and lean proteins like fish and chicken. It’s important to limit processed foods like meats, cheese, salt and sugary snacks and drinks and insure that your food is nutrient-rich. Consistent exercise and maintaining a weight within 5-10 pounds of your ideal weight is key. Guillar maintains that “Controlling well-established risk factors such as blood pressure, cholesterol and glucose levels is an effective way for individuals to reduce the risk of disease” .
There are a few other considerations regarding multivitamin use. Since there’s little FDA oversight of their manufacture, they may not contain the potency values listed on the bottle. Also, taking a multi-vitamin when unnecessary will just result in expensive urine – excretion of most of what you ingest. It’s always a good idea to consult with your doctor if you begin taking a multivitamin and have a medical condition that would contraindicate its use. Taking more than the stated dosage, or in combination with other vitamins and supplements can also result in unwanted side effects. Too much of certain vitamins may be harmful.
So, what’s the take-away? If you suspect you have a vitamin deficiency, manifested by excessive fatigue, numbness, muscle weakness, or other noticeable symptoms, you should get lab tests to determine if you actually have one, or if these symptoms are a result of another disorder. If you do have a vitamin deficiency, a nutritionist or physician can prescribe the right diet or supplements to help your specific condition. If you’ve been taking multivitamins, have no adverse effects, and believe they help you stay strong and healthy, continue, but know that you will excrete whatever is not needed. If you eat a healthy diet, and have none of the above symptoms, you likely do not need to begin taking one. Getting adequate sunlight, eating a diet rich in the foods mentioned earlier, controlling risk factors through regular check-ups with a physician, and last but not least, regular exercise are your best bets for long-term health and longevity.