The following is an excerpt from The Campbell Plan, which was just released by Rodale Books.
Many people view multivitamins as some sort of insurance policy that they use so they’ll feel that they’ve got their bases covered when it comes to nutrition. Unfortunately, it’s an insurance policy that won’t pay out and in some cases may be harmful, but people have been buying and taking multivitamins since the first one was introduced in the 1940s. I never recommend a multivitamin for general health. I think it’s a waste of money, and generally the scientific authorities agree.
A National Institutes of Health State-of-the-Science Panel was convened to examine the issue of vitamin and mineral supplements for the prevention of chronic disease. By “chronic disease,” I mean illnesses like cancer and heart, endocrine, musculoskeletal, neurological, and sensory disease, among others. The expert panel found that “the present evidence is insufficient to recommend either for or against the use of multivitamins by the American public to prevent chronic disease.” Evidence suggests that multivitamin supplements do not protect against cardiovascular disease.
There are conflicting studies on multivitamins’ effect on cancer. Some studies have shown some small benefits, while others have actually shown an increased risk of cancer, most famously the trials showing higher rates of lung cancer among smokers taking betacarotene. There have been some studies showing benefits with certain vitamin and zinc formulations for eye health, specifically macular degeneration, but not cataracts.
In general, the story of multivitamins is a perfect example of reductionism in nutrition research. The pattern that continues to repeat is that observational studies (in which scientists simply record and analyze factors and outcomes, without intervention) find that those people with higher intake or higher blood levels of single vitamins have lower rates of certain diseases. Rather than stop there and focus on trying to get everyone to adopt healthier dietary patterns with more of those vitamins, researchers progress to studying whether pills with those isolated vitamins or minerals can have the same beneficial effect. Isolated nutrients will never have the same beneficial effect as healthy whole foods, as has been shown time and time again in repeated failed trials of vitamins. This is covered in greater detail in The China Study and in Whole.
In addition, multivitamins are not necessarily benign. There is evidence in some studies that risk of certain cancers in some patient groups is increased with supplement use. In addition, there may be a higher risk of kidney stones and heart attacks in those who use calcium supplements. Vitamin and mineral supplements can be a significant cause of poisoning in children, and birth defects and liver damage have been associated with excess vitamin A ingestion. The National Institutes of Health panel wrote, “There is evidence, however, that certain ingredients in [multivitamin/ mineral] supplements can produce adverse effects. …….Although these studies are not definitive, they do suggest possible safety concerns that should be monitored for primary components of multivitamins.” For all of these reasons, I propose that you avoid a general multivitamin supplement for maintaining overall health.
Read more about how healthy food can do more for your health and your life than any pill in The Campbell Plan. In it, Dr. Campbell uses the latest scientific research to create a practical and easy-to-follow plan that will help you lose weight and reverse illness.