EDIT: The study was also performed exclusively on patients who presented with acute coronary syndrome. Average age was over 60, nearly 80% were men, and half had already had at least one heart attack. Keep that context in mind when reading numbers about the patients in the study. This is a heavily biased sample, which is fine for the purposes of the study but important to remember.
> Participants in the experiment arm who stayed within 40-80 ng/mL of vitamin D had a 52% lower risk of a repeat heart attack.
The study did use supplements to get people into that range if necessary, but the important thing is to keep your Vitamin D in that range, not specifically to just take supplements.
There’s a lot of claims online that everyone’s Vitamin D is too low and we should all be taking very high dose supplements, but it’s getting exaggerated. My doctor said she’s seeing a huge number of patients coming back with excessively high Vitamin D levels after taking supplement doses recommended by influencers. It happened to me, too, with what I though was a conservative dose of Vitamin D (5K IU, not even taken every day)
So you really have to check. Even though I work indoors and wear sunscreen a lot, apparently my diet and limited sun exposure alone are sufficient for staying in this range. Others will have different results. Don’t guess!
Also remember that Vitamin D levels change slowly. Supplementation can build up and accumulate in the body over time if you’re taking too much. You want to stabilize on a dose and then check in 3-6 months. Some people get a low Vitamin D result and start taking high doses every day, then a year or two later they’re into hypervitaminosis D and have no way to clear it other than waiting for it to be processed out.