It's too bad you can't get vitamin D from lasagna. Or, wait...what if you could...
Vitamin D is damnably hard to get in the way we get most of our other nutrients, namely through our diet. But there is one group of foods that can supply a pretty decent amount, and it’s not one you might expect.
Yep: mushrooms. But before we get into how and why (and a way to boost your mushroom’s vitamin D supply even more!), let’s talk vitamin D.
Vitamin D is a weird one in terms of vital nutrients; in fact, it’s sometimes considered a hormone and not a vitamin, because you don’t typically get more if it by ingesting. Think of vitamin C, perhaps most often associated with citrus fruits like oranges: You get it by eating an orange. But vitamin D is synthesized by the body itself.
Sunlight hits the skin, and the UVB radiation is absorbed into the body in the form of vitamin D. But it’s not useful yet; it has to be carried through the bloodstream to the liver, where it’s converted once, and then to the kidneys, where it’s converted again. Then it’s carried again by the bloodstream to bones and organs where it’s needed.
After all that conversion, the new vitamin is used by the body to facilitate the absorption of other minerals; without enough vitamin D, you can ingest plenty of calcium, iron, zinc, and other minerals, but your body won’t be able to actually make use of them. That quality makes vitamin D essential for bone health. It’s also been comfortably connected to the promotion of immune health, though most other claims (anti-cancer, anti-depression, anti-heart disease) have not been conclusively proven either way.
There are a few different compounds grouped under the “vitamin D” banner, but the most important are typically referred to as vitamin D3 and vitamin D2. Vitamin D3 is the type that your body synthesizes with sunlight, while vitamin D2 is more easily retrieved from foods. Supplements containing both are available, but D3 is harder to find, and also is made from animal products, which might put it off-limits for those with certain diets. Comparisons of the two have generally found that D3 supplements are more easily converted by the body and last longer, but a 2012 analysis of the studies on the topic found that for daily, low-dose supplements, vitamin D2 is just as effective.
But supplements aren’t the only way to get vitamin D2: Mushrooms have been shown to be in the very rare group of foods (along with lichen, some oily fish, and alfalfa) to contain significant amounts of vitamin D. A 2013 study found that the effects of those eating mushrooms (well, mushroom powder, but still) were identical to those taking the same amount of vitamin D2 supplements.
The craziest thing? Exposing mushrooms to sunlight – seriously, just, like, placing mushrooms in the sun – causes them to act like solar panels and such up and create much higher levels of vitamin D2. Sun-dried (or even artificially-UV-light-dried) mushrooms can have dramatically ramped-up vitamin D2 levels, although most commercially dried mushrooms are dried indoors.
We won’t insist that the consumption of mushrooms (or vitamin D in general) will have any kind of dramatic effect on your life; if you’re out and about even a little, you’ll absorb enough sunlight to be perfectly healthy until warmer weather comes. Still: what a weird thing!