by Marion Nestle
Jun 18 2007

Foods vs. Supplements

A writer for a women’s magazine asks: If you want to get more of a specific nutrient (lycopene, for example), is it better to take a dietary supplement or to eat foods containing that nutrient? What benefits do you get from eating a whole food that you might miss if you took a supplement instead?

My response: Unless you have been diagnosed with a vitamin or mineral deficiency and need to replenish that nutrient in a great big hurry, it is always better to get nutrients from foods—the way nature intended. I can think of three benefits of whole foods as compared to supplements: (1) you get the full variety of nutrients—vitamins, minerals, antioxidants, etc–in that food, not just the one nutrient in the supplement; (2) the amounts of the various nutrients are balanced so they don’t interfere with each other’s digestion, absorption, or metabolism; and (3) there is no possibility of harm from taking nutrients from foods (OK. Polar bear liver is an exception; its level of vitamin A is toxic). In contrast, high doses of single nutrients not only fail to improve health but also can make things worse, as has been shown in some clinical trials of the effects of beta-carotene, vitamin E, and folic acid, for example, on heart disease or cancer. And foods taste a whole lot better, of course. For more on this, see chapter 37 in What to Eat on “Supplements and Health Food.”

  • I am reading your book, What to Eat, and finding it very helpful. Could you comment a bit more about folic acid supplementation – specifically on its benefits in preventing neural tube defects vs risks involved in taking too much folic acid as a supplement on a long-term basis? Thanks!
    Ed Dodge

  • Sure, but this area of research is complicated. Researchers mostly agree that adequate levels of folic acid before pregnancy protect against neural tube defects–the rationale for fortifying flour with that vitamin. Since fortification, blood levels of folic acid in the population have increased and rates of neural tube defects have declined (but the rates were declining at the same rate before fortification). A few recent clinical trials of folic acid supplements for other diseases have shown no benefit, however, or slightly worse outcomes (I am away from my office this week and can’t provide specific references at the moment–
    perhaps readers know what they are?). My take: Folic acid is present in fruits and vegetables. In contrast to the situation with supplements, eating such foods regularly is well established to be good for overall health. Anyone else have thoughts on this?

  • Thanks for your quick response! The most recent study I am aware of was in the JAMA in May this year. It showed that folic acid supplementaion at a level of 1 mg daily in patients who had an established diagnosis of colon polyps had almost twice the incidence of more aggressive lesions five years into the study, as compared to those on placebo – which was a big surprise. The conclusion was that folic acid did not protect against development of more aggressive lesions, and that more ressearch was needed to define the situation with regard to folic acid more clearly. Still, it was a solid enough study to earn an editorial in JAMA, and make me feel cautious about folic acid supplementation. It also makes me wonder about ongoing folic acid fortification of foods. I’ll be interested in anyone else’s thoughts on this.
    Ed Dodge

  • L Young

    I currently take a standard multi-vitamin, but have heard alot about whole food supplements lately. What is your position on whole food supplements?

  • Well, they won’t have as many calories as foods so they have that going for them, but pills are processed and processing always causes nutrient losses. I’d stick with foods. They taste better.

  • Cady

    Dr. Nestle,

    I found your blog while searching the net and after reading a few entries, I plan on buying your book. I searched the topics on your site and see you don’t talk about vegetarianism. I can’t classify myself as a vegetarian (something I NEVER thought I’d be) because I eat the OCCASIONAL chicken breast and turkey sandwich but I no longer like red meat. I’m concerned that I’m not getting enough nutrients, especially protein, with what I’m eating.

    I’m also concerned about my fish intake – and too much “good fat” – because in place of chicken I’d much rather have salmon, tuna, etc. and then I think I have to be careful of eating too many avocados and walnuts.

    I take a daily vitamin and had my blood tested recently to make sure I’m not anemic and that came back normal. On a typical day I eat oatmeal for breakfast, a salad for lunch, yogurt and fruit or trail mix bar for a snack and then dinner is a toss up. Any suggestions or recommend any books? Thanks for your help!

  • Dr. Nestle
    Can you comment on the recent studies showing Vitamin D’s protective affect against breast and other cancers, specifically:

    1. Should we supplement with (at least) 1000 IU/day, like the Canadian Cancer Society recently told its population to do?

    2. Should we all be getting more unprotected sunshine than we do as a result of being scared out of the sun in the late 80s?

    3. Should most of us be more concerned about internal cancers than melanoma?

    Thanks. I’ve linked to the Vitamin D Council. Not my site, but one I refer to often for all the latest health news on Vitamin D.

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