To Multivitamin or Not to Multivitamin?

Introduction

About 30% of adults in the western world take a multivitamin. Multis alone make up about 40% of all vitamin and mineral supplement sales. However, research evidence supporting the use of multis is mixed at best with recent large population studies reporting no association between use of multis and better cardiovascular or brain health, and only modest cancer protection. In contrast, one 2011 study, the Iowa Women’s Health Study, showed an increased risk of death in women who took multis.

I’m aware of these ‘fors’ and ‘againsts’ and have for year taken a daily multivitamin (and Flaxseed oil – source of Omega 3, 6 and 9). I eat very healthily with plenty of natural cereals, 5 servings of vegetables a day and at least 3-4 serves of fruit a day. However, I’m also very active exercising 1-2 hours a day. My belief is that despite eating a nutritious and well-balanced diet, my multi a day might cover my butt with any dietary deficiencies I may have in vitamins and minerals.

Recently I found a great discussion paper in a journal where four experts from Tufts University in the USA discussed their thoughts on use of multivitamins. One was a professor and director of an antioxidant research laboratory, one a professor of nutrition and contractor to the Office of Dietary Supplements in the USA, one a professor of nutrition science and director of a cardiovascular nutrition laboratory, and the other a professor and director of a vitamin and cancer lab. Collectively, world leaders in the field I feel!

What were the main points raised?

  1. Multis are not harmful and help fill the inadequacies in the average requirements for vitamins D, E and K and minerals magnesium and potassium that about 60% of Americans fail to meet. Moreover, about 40% of them fall short on vitamins A and C. Why are this happening? Because sadly people aren’t eating fruit, vegetables and whole grains where collectively all these great vitamins and minerals are found. In general masters athletes like us tend to be well-educated and eat well. So maybe we don’t need multis if we are eating natural foods and not hammering the junk food and take-aways!
  2.  Not every person needs a multi.Some examples where they might be needed include:
    • the very old and / or frail who don’t eat a lot
    • people with disease or illness who may not eat well
    • athletes who train hard and / or long and are not getting enough energy intake in a day so are losing weight
  3. People who might need supplements such as iron or calcium supplements should be taking these supplements and not a multi. The belief that a multi contains enough of a particular vitamin is wrong. In general, the amount of any one vitamin and/or mineral in a multi is not enough to make up for a problem a particular individual may have. This is where a dietician or doctors input is critical.
  4. If you are shown to have an inadequacy in a vitamin or mineral look for a natural food solution rather than a pill. For example, the intake of the mineral calcium and vitamin D is often found to be inadequate in older people, especially in post-menopausal women who don’t get much sun, including older female athletes. So is low-fat greek yoghurt or increasing your dairy intake a better option? These experts think so!
  5. What about the 2011 study that said women who take multis are at higher risk of death than those that don’t? This study has not been supported by other studies since. Moreover, it did not tightly control for other factors that may have contributed to deaths such as smoking, obesity and pre-existing illness. The consensus at present is that taking multis does not increase how long we live but equally it does no harm either. A recent study called The Physician’s Health Study II tested a complete multivitamin in 15,000 men and actually found a reduction in cancer incidence in those men who took multis. They also controlled for confounding variables like smoking.
  6. Taking too much of a vitamin does not appear to be an issue. Except taking too much vitamin A which has been linked to bone loss.
  7. Bottom line is to personalise your intake of vitamins and minerals based on your nutritional intakes, health status and exercise habits. While a multi may not do any harm, they have small amounts of everything and may miss something you as an individual may need. Chat with your doctor or dietician is my suggestion.

Source:  Should you take a multivitamin? Four Tufts experts tackle the multi-billion-dollar question, Tufts University Health & Nutrition Letter Sept. 2015.