Vitamins Don't Work

In Victoria, Australia from 2003 to 2005 thousands of elderly women were enrolled in a study that researchers thought might represent the future of geriatric health. For five years the women were given a single annual dose of Vitamin D, or a placebo. From earlier small studies experts surmised that Vitamin D, which helps bones absorb calcium, would prevent hip and other fractures, potentially reducing suffering, preserving function, and lengthening lives.

When the results were tabulated the researchers found good news, in one sense: the shots consistently and meaningfully raised Vitamin D levels. The bad news? Vitamin D increased fractures by 26%.

The vitamin shot, it turned out, induced falls by causing dizziness. This trial, and a few dozen more, are why the United States Preventive Services Task Force recommends against routine Vitamin D supplementation.

Which was hard to process, for me. I was taught to believe vitamins were the bomb. As a kid I took daily Flintstones and spent countless hours learning about the benefits of vitamins from the backs of cereal boxes. I even knew that Ovaltine, my favorite chocolate milk powder, was “fortified with 12 vitamins and minerals!”

Which, it turns out, is precisely why it’s banned in some countries. Denmark, for instance, figured out that while deficiencies are exceedingly rare in developed settings, vitamin overdoses and misleading claims of benefit are common. Health authorities there look with suspicion at ‘fortified’ products, and typically disallow them.

This stands in stark contrast to the American obsession with vitamins, where the market for vitamin supplements is estimated at around $150 billion (and growing). This is despite huge reviews of randomized trials finding no benefit to either multivitamin combinations or single vitamins. And while the studies aren’t perfect, and don’t cover every possible use, it is safe to say daily vitamins do not, for instance, prevent deaths from cancer or heart disease.¹

What’s tricky, however, is that many people taking vitamins do so not to stave off death, but to boost energy, or joint health, or eyesight, or hair growth, or weight loss, or anxiety, or muscle strength, or halitosis, or Wordle, or mind-reading, or time travel, or whatever.

And YES, for honing memory one recent trial suggested a possible benefit with multivitamins—but alas, it is weak data showing a tiny, probably meaningless effect, while large reviews of trials have repeatedly failed to find the same benefit. This sequence, where one or two studies finds a small, questionable benefit but large reviews of many others find nothing, is the rule and not the exception.

On topics like mind reading, however, the research is silent and will remain so. Not just because mind reading is tough to study, but because the VITA-MIND® study (I call naming rights), in order to be reliable, would have to be well funded, well designed, and executed by professional scientists. Big Vitamin won’t be sponsoring that trial anytime soon. For snake oil salesmen, touting snake oil with no data is waaaay more lucrative than sponsoring rigorous trials that are likely to end the charade.

In an ideal world the NIH or other public interests would sponsor such trials, offering a reliable source of evidence. In some cases the NIH has done just that, which is why we know vitamins don’t work for cancer and heart disease. But the NIH is not likely to spend millions evaluating whether Vitamin Q improves patience with the in-laws.

In summary, vitamins aren’t vital. At least not as supplements for healthy people in developed settings, where food has more than enough nutrients. People with symptomatic vitamin deficiencies should take vitamins, and women in early pregnancy or trying to get pregnant should take folate. Everything else is proven not to work, or not proven to work—a loophole that generates endless profits. (Ah, the power of placebo).

Which is why vitamin Q, for now, can act like a perfect cure for in-law anxiety.

1. Nearly a million people have been in randomized trials testing these questions, and there are no benefits. Vitamin advocates, and there are many, will cry foul here, mostly saying the vitamins weren’t the right preparations, or the doses were wrong, or the people were the wrong people, or whatever. But study after study after study shows zero benefit (or less commonly a tiny meaningless claim of benefit), from different groups in different populations across different types of vitamins, and ALL of the studies are done by true believers who thought they would find a benefit. To me, this suggests that if anything the biases of these studies probably led to concealed harms, and that vitamins may be more dangerous than we know. In any case, there is definitively no evidence of any benefit despite lots of hopeful studies.