The headline is poorly worded. The 52% number was for people with Vitamin D levels within a certain range, whether or not they took supplements

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.

▲

detourdog 7 hours ago | parent | next [-]

I don't doubt you but I also wonder what you base this information on.

In 2020 I test results for vitamin D was ridiculous low. I have been taking supplements

Jan 02, 2020 4:32 pm 25-Hydroxy Vitamin D Total 9 ng/mL 30-100 ng/mL

I took me five years just to get to something close to the lowest end of normal.

I was started on supplements in the in 2k IU and after poor progress boosted to 5k IU everyday to get to this level.

I have been spending the past year on a sailboat instead of server room and look forward to seeing my test results.

▲

tylerhou 6 hours ago | parent | next [-]

A big problem is that the range that we have decided to call “normal” might not actually be a normal range.

For example, 50% of surfers were found to have insufficient vitamin D in one study. https://pubmed.ncbi.nlm.nih.gov/17426097/

There are at least two possible conclusions that you could draw. One conclusion is that we all need vitamin D supplementation regardless of how much sun exposure we receive.

Another conclusion is that we might want to reevaluate what we consider the normal range to be, especially when we are deciding a range for a specific individual.

	▲	relaxing 4 hours ago \| parent [-]
		No, the conclusion is surfers are conscious of their exposure and wear sun protection.

▲

Aurornis 7 hours ago | parent | prev [-]

My own experience getting a too-high result from supplementing 5K IU several times a week. When it came up, my doctor said I wasn't alone and that she's seeing a lot of people come back too high.

> I took me five years just to get to something close to the lowest end of normal.

Five years of supplementing to get up to 30ng/mL? Something is wrong. Could your supplements have not actually contained any real amount of Vitamin D? Certain malabsorption disorders also reduce Vitamin D absorption, for example.

	▲	seba_dos1 3 hours ago \| parent \| next [-]
		Five years is unusually long, but your case is an outlier too. Usually it will take about 3 months to rise serum levels by ~30ng/mL on 5K IU daily, though there's plenty of individual variation of course. It's a low enough dose that if I had to choose between taking it blindly or not taking it at all if I was so depressed I couldn't get out of bed to get my levels tested, then I would do it blindly for a month or two without second thoughts.
	▲	fragmede 5 hours ago \| parent \| prev [-]
		Don't forget your K2!

▲

brandonb 7 hours ago | parent | prev | next [-]

> 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)

IMO that’s part of what’s interesting about this study design — they tested vitamin D blood levels and adjusted the supplement dose based on that. This seems like a much better approach than taking a high dose blindly.

I think the headline is accurate. The 52% number is from the experiment arm (participants who received a vitamin D supplement, with the quantity guided by blood testing). While it’s technically possible for the supplement dosage to be calculated as zero, 85% of participants were deficient at baseline, so this isn’t the main effect.

▲

Aurornis 6 hours ago | parent [-]

> I think the headline is accurate. The 52% number is from the experiment arm (participants who received a vitamin D supplement, with the quantity guided by blood testing). While it’s technically possible for the supplement dosage to be calculated as zero, 85% of participants were deficient at baseline, so this isn’t the main effect.

Yes, but it's also important to note that the study wasn't on a representative sample of the general population. They recruited people who had acute coronary syndrome. The average age was over 60 years old, 80% were men, and half of them had already had at least one heart attack.

	▲	detourdog 5 hours ago \| parent [-]
		I think the supplements are just average Vitamin D off the grocery store shelf. Malabsorbtion is obvious possible.

▲

tim-tday 5 hours ago | parent | prev [-]

If the vitamin d levels are not due to supplements the answer is that people who go outside get more sun and more exercise.