Dear GreenSmoothieGirl: Should I take multivitamins? If so, which kind?
Whole foods, 60-80% raw, what I teach you, covers your nutritional needs. One of the tougher things to get from your diet is omega fatty acids, but a little bit of flaxseed, or flax oil, several times a week (or fish oils, a more problematic source), will cover that. A variety of greens, vegetables, fruits, legumes, nuts, and seeds (in that order) will give you the nutrition you need.
Synthetic vitamins give you a false sense of security. People ill-educated about nutrition (which is almost everyone in the modern world) think that multivitamins cover a multitude of sins. (“I’m okay to eat this Quarter Pounder because I took my One A Day!”)
The pills you’re taking are, at best, parsed bits of foods, but usually they aren’t even derived from foods–they’re cheap synthetic (chemical) derivatives or imitations. Apparently your body doesn’t use them like it uses nutrients in the complete, beautiful little packages you find in kale, lentils, and bananas. How do I know this?
Because huge meta-studies (surveys by scientists of many pieces of research) yield pretty consistent, dismal conclusions about whether multivitamins or individual vitamins are really netting us anything. The conclusion: they’re not.
In fact, in some cases, vitamin pills are causing overdoses. This is my blog, not a research paper, so I’m light on sources here. But you can google on this or search research databases. You’ll very easily read about how, for instance, an examination of 40 years of research on Vitamin E shows overdosing can hurt you:
Are there exceptions? Sure. Not many. Two examples: First, folic acid for pregnant women prevents some birth defects and cancers. (That said, I believe the iron pills routinely fed to pregnant women is toxic.)
Second, Vitamin D for those who don’t live near the Equator.
Right now Vitamin D supplementation is new enough that I am waiting for more longitudinal evidence.
Meantime, because most of us in North America and Europe are terribly deficient in exposure to sun, Vita D in the form of pills is likely a good idea. That’s my verdict for now as I watch and wait. (I have documented my own Vita D tests following a summer of sun, and following 400 IU supplementation all winter, an insufficient amount. My levels were pretty good but fell significantly from sunny July to long-dark-winter March (after taking D supplements all winter). This winter, I am dosing higher. Thanks to a foot injury, I was not outside in the sun nearly as much “tanking up” on Vita D, since tennis and running were off limits most of the summer.
Here’s a PubMed meta-analysis of the Vitamin D efficacy debate showing some benefits:
But, here are some nuggets from medical annals’ dismal conclusions through meta studies on multivitamins:
1. “The evidence for routine use of multivitamin and mineral supplements to reduce infections in elderly people is weak and conflicting.”
2. There’s “no evidence to support antioxidant supplements to prevent mortality in healthy people or patients with various diseases.” (The Cochrane Collaboration in 2009 looked at 67 trials involving over 230K subjects taking beta carotene, Vitamin A, C, E, and selenium). In fact, they found higher mortality in some trials, from Vita E (none of the other supplements were linked to higher mortality).
3. Another meta study by Johns Hopkins concluded: “Evidence is insufficient to prove the presence or absence of benefits from use of multivitamin and mineral supplements to prevent cancer and chronic disease.”