Hamblin: If you can add a multivitamin and not change anything, then go for it. Whatever. I mean, you might waste your money.
Wells: Is there really no science behind a vitamin being good for you?
Hamblin: Not unless you have a deficiency in any of those areas.
Wells: And do people generally have deficiencies? Does our modern diet mean you have some deficiencies?
Hamblin: No, you need so little. And anything that you would be likely to get deficient in, we fortify. Even pastas and cereals, they’re fortified with vitamins in case you do just eat packaged foods all the time and never eat fresh produce.
Wells: You’re telling me that, like, my Cheerios have a multivitamin in them?
Hamblin: Oh, yeah. They’re loaded with vitamins. The reason there’s vitamin D in milk is because we add it to the milk. We found ways to make an ultra-processed diet that would avoid vitamin deficiencies. And that’s actually a problem for us.
Wells: So our diet is already basically the equivalent of a multivitamin, where we’ve just randomly put vitamins in the crap we eat?
Hamblin: That’s what fortification is. It’s one of those things that is sort of like oxygen. You are getting enough and getting more is not going to help you. The one outlier in the coronavirus-vitamin discussion is vitamin D. There’s almost nothing in our diet that gets us vitamin D. It shouldn’t even be called a vitamin, in my humble opinion.
Wells: What is the definition of a vitamin?
Hamblin: There is no definition. It’s derived from this marketing term, vital amines. We thought they all had an amine group on them and turns out they don’t.
Wells: That’s what “vitamin” is?!
Hamblin: Yeah. A great book on this is Vitamania, by Catherine Price. It goes into the whole supplement industry and how these ideas started.
Wells: What are vitamins?
Hamblin: It’s a random smattering of compounds. We call them “micronutrients,” as opposed to, say, macronutrients like fats, carbohydrates, and proteins. “Micro-” nutrients are these tinier ones, which you need, like, the amount of the head of a pin every month. Most of them occur in food. Vitamin D is one that doesn’t. You make it yourself being out in the sun. And you don’t need a lot, just a few minutes.
There is not evidence that laying out and tanning is good for you. That’s still a major cause of skin cancer. As long as you have some exposure, even just sitting near a window, that should be fine. But there are some serious researchers who believe that there are people who are in a gray area, who might not be getting enough vitamin D, especially when told to stay home. When you’re really limiting outdoor exposure, it could be good to take a supplement.
Wells: So it’s not that vitamin D somehow fights off the coronavirus. It’s that if you don’t have enough vitamin D—and there could be a slightly elevated percentage of people who don’t have enough vitamin D, because we’re all staying inside a lot—then your immune system can get all wacky, and therefore you would want to take a supplement. What about vitamin C? At the beginning of this, I was taking a vitamin C supplement every day.