[damla]

While one supplement is in trend, as now with vitamin D, when you search and try to make a decision if you should supplement it, you always end up deciding it is beneficial, or at least doesn't hurt to. But as the trend fades, you may find that it is not that important or even harmful to overdose in specific situations.

So I am skeptical of supplements as a rule. Of course there are a couple of odds, like iodine, which is so beneficial to supplement in general community, that it is added to table salt as default, you only skip if you have specific conditions like thyroid problems.

I wish there were more research or comments on possible harms and disadvantages of excessive use of vitamin D, than I think I could more easily decide to use.

[IkmoIkmo]

I really don't see the issue. All vitamin d sales come with daily dosage information. There's (always going to be) some issues with literacy to understand this information, but that's it.

If you follow the daily dosage information, you won't even get near harmful levels of vitamin d. Recommended is about 600 IU daily. If you take 60.000 on a daily basis for months, you build up toxicity.

For that you typically need to take 30 pretty strong 2000 UI pills on a daily basis for months, while ignoring the label that states each pill is typically 250% of the daily recommended amount, and the instruction which notes the tolerable levels max out at just two daily pills.

Toxicity is extremely uncommon. Whereas deficiency is extremely common. Up to a billion people are expected to have some form of vitamin d deficiency.

That's not to say it's not a problem, but rather that it's very rare, nothing like say an opioid overdose problem. As with all things, balance is key. You can overdose on 5 cents of water in the span of 5 minutes. Acute vitamin d overdose is known to happen if you take something like 300-1000 pills of 2000 UI over a period of days, which is pretty insane.

[jp555]

You reminded me of a paper that suggested that there was an error made in developing the RDA of Vitamin D; the 600IU RDA may be wildly wrong.

“ It also estimated that 8895 IU of vitamin D per day may be needed to accomplish that 97.5% of individuals achieve serum 25(OH)D values of 50 nmol/L or more.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/

[blurbleblurble]

It's important when megadosing vitamin D to be getting enough magnesium, and to make sure you're taking it earlier in the day, so as not to disrupt your circadian rhythm.

[HaukeHi]

You can definitely overdose:

https://en.wikipedia.org/wiki/Hypervitaminosis_D

[pezo1919]

But from the same article:

Hypervitaminosis D symptoms appear several months after excessive doses of vitamin D are administered.