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Comment by fumar | Hacker News Reader

We need to understand the impact of increased vitamin D on vitamin D average vs vitamin D deficient people. I was vitamin D deficient, lowest part of the spectrum, and since taking daily supplements I noticed less health issues overall. I believe it also helps with my sleep cycle. YMMV I am regularly tested for vitamin D and its consistently above average, but you must monitor to not exceed the threshold.

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Also make sure you're getting your calcium levels tested as too much Vitamin D can lead to hypercalcemia.

thanks for sharing, never knew this. Got a good source to read more up on it?

Vitamin K2 can address that: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4566462/

I take K2 with vitamin D. Good call.

I had hypercalcemia and it was causing me headaches and short term memory loss. Two things i cut off that helped a lot 1. Vit d 2. Sony noise reduction headphones

For a daily dose as low as 2000 IU this is not going to be a concern for adults, especially when taken with a meal. Generally for avg+ weight males, even 5000 IU with a large meal is not going to cause issues with hypercalcemia.

Look to avoid added calcium in multivits first. Women and those concerned with bone health should supplement with boron instead. Dietary calcium should be more than enough in typical diets. The only calcium containing supp i might take would be calcium ascorbate (it's a fairly small dose of calcium).

Having wattage emitted in RF bursts 2mm from your head is never a good idea (yup, i wholly approve of avoiding this: "2. Sony noise reduction headphones").

i've been skiing 3-4 days/week with around 8 hrs out in the sun. Would this have the same beneficial effects on me? I am always deficient but i din't bother taking anything so far due to lazyness.

For Vitamin D synthesis, the sun needs to be at an angle of 50 degrees or higher. Depending on the latitude where you live, the sun may not get that high all winter so you may need to supplement.

Surely sunlight is still sunlight even if it's from a low angle?

From memory, it's not just about sunlight, but rather specific band of uv-light; and the atmosphere filters it when the sun is at specific angles. It's not as simple as "just sunlight".

No, the composition of sunlight literally changes throughout the day. When the sun is low in the sky in the morning or evening, light is traveling through more atmosphere than it is at noon. As light travels through the atmosphere, a certain fraction is scattered in a wavelength-dependent way. UV-B light--the Vitamin-D-causing kind--has a hard time passing through the atmosphere because of interactions with ozone molecules, so at grazing angles almost none gets through. However UV-A light is less affected by ozone and can still give you a sunburn. Interestingly, ordinary glass blocks both.

Unless you ski naked its not doing much .

Do you just swallow a pill?

Yep, it's the most insanely underappreciated public health intervention in history.

Many public health people say that iodized salt takes those laurels. Or maybe its the most bang for the buck, at an estimated $.05/person/year to prevent intellectual and developmental problems. Guess it depends on exactly what you mean.

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

Vitamin D is a fat soluble vitamin isn't it, so maybe we need more than just swallowing a pill. We have very bad data from most Vitamin D studies suggesting it does almost nothing. The people with high natural Vitamin D who spend 1-2h per day (exercising?) outside might just imply a proxy for a healthy lifestyle.

Alternatively Vitamin D might need to be a) taken in higher quantities than the studies have done b) taken with fat c) taken with other supplements K2, NAC, Magnesium (which people are also deficient in) etc.

We could probably come up with other theories why the trials and results don't add up. Nice to see an actually positive result from supplimentation.

>> who spend 1-2h per day (exercising?) outside might just imply a proxy for a healthy lifestyle.

Try living in the north. Being outside, exercising, and sunlight exposure are three unrelated activities for at least six months of the year. Vitamin D supplements are the only way short of tanning lamps.

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