Why Supplements are Suspicious

December 16, 2013 in Uncategorized

We’ve been taught to think of food in terms of what we need. Lacking vitamin A? Eat a carrot. Need calcium? Drink milk. But food does a lot more inside our bodies than nutrients ingested in pill form. There is almost no direct relationship between nutrients consumed and nutrients actually reaching its “main site of action in the body”. This is known as bioavailability.

Whether a vitamin will be utilized or not is unpredictable, because it depends on the body’s needs at the time. The body chooses what to use and what to discard. Therefore, we can’t just throw large doses of nutrients into a supplement and call it good.

“The pathway that nutrients take often branches, and branches further, and branches further again, leading the nutrient through a maze of reactions that is far more complex and unpredictable than the simple linear model of reductionism would suggest.” – T. Colin Campbell

Not only do nutrients in food vary; whether our body will absorb or not them does too. Nutrient content in the same foods varies dramatically. For example, the beta-carotene content in two peaches varied by 40 times, depending on season, soil, storage, processing, and location. Nutrients can also modify one another’s activities. “Calcium decreases iron bioavailability by as much as 400%, while carotenoids (like beta-carotene) increases iron absorption by as much as 300%.”

The common belief that we can know the effects of a single nutrient while ignoring other factors is foolish. We should be suspicious of “mega-doses” that are isolated from whole foods. We have evolved to eat whole foods, not vitamin E injections.

Only a miniscule percentage of total nutrients are even identified. The body is simply too complicated for us to know what kinds of chemicals are consumed in a single meal. The good news is that nature knows what it’s doing. We don’t need to know every single detail about the complex system of nutrition – not only do we not need to – we can’t.


Campbell, T. Colin, and Howard Jacobson. Whole: Rethinking the Science of Nutrition. N.p.: BenBella, 2013. Print.