It could also be that many of us have seen studies over the past few years about the general issues with Vitamin D deficiencies, so, in addition to the recent studies; it doesn't seem like such a leap that something as simple as increasing Vitamin D could benefit covid protection/recovery.

Right. We know most people have lower levels in winter. There is reason to believe it helps. There is little reason to think it may harm - particularly in light of the seasonal deficiency. Why would anyone not think it's worth trying? I've been wondering why the CDC hasn't recommended it yet.

Well, is it wrong?

And programmers seem more likely to spend their time indoors, and therefore more likely to be vitamin-D-deficient without supplementation.

I was tested severely deficient. Didn't have any obvious symptoms either.

The main problem of a vitamin D deficiency is poor bone and muscle health, not something that would usually cause obvious symptoms.

One of the hallmarks is lower back pain. If you get this frequently for no explicable reason you should be looking to get your levels tested.

Sleeping well? Were you waking up refreshed in the morning?

A lot of programmers don't sleep well regardless of their vitamin d intake. Late work, blue light all day, not enough exercise, stress, etc.

Not exactly. However, I've been taking Vitamin D for a while now and I can't say that feel "more refreshed".

I would guess that it depends on what your current vit D level is. Also, depending on your genotype you might be a fast or slow metabolizer of vit D, which would also play a role in how big of a dose you would need.

I recommend the talks/interviews by Dr. Stasha Gominak a neurologist specializing in sleep.

I have done 1000 IU for a few months with no impact on chronic insomnia.

The recommendation is 5,000 to 10,000 iu. 1,000 is what the label on the bottle says.

According to whom? NIH says 600 IU for a normal adult (https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona...) and recommends a maximum daily intake of 4000 IU (https://ods.od.nih.gov/factsheets/VitaminD-Consumer/).

My doctor specifically prescribes 5000 IU as a maintenance dose and 15000 IU to people severely deficient. These are numbers he got from treating hundreds of deficient patients and testing his patients blood levels every 6 months. I imagine a lot less is needed if you are in the sun for a good portion of the day every day but for most of us who spend a decent amount of time inside it seems to be what’s necessary.

My experience correlates with your doctor's: I had to take more than 5000 IUs per day for about 3 months to reach the bottom of the normal range for 25-OH-vit D.

Did you read the open letter (original link of thread)? There is an entire paragraph and footnote with 2 refs talking about the problem with the current government guidelines.

I've been doing 4,000 iu/day of Vitamin D since March, also supplementing Zinc and C, and taking a standard multivitamin. My entire household got COVID in November and I never became symptomatic.

The HN crowd is fascinated by simple but effective "hacks". This appears to be one.

The rest of the world is fascinated by simple but effective "hacks" like wearing a mask. There are a lot of simple hacks that end up being real.

Both masks and Vitamin D are helpful and those at risk or in areas of great spread should consider both. This is similar to masks and face shields offering a multiplier effect. The big difference is that sufficient Vitamin D levels are strongly correlated with numerous metrics of good health including immune, metabolic, and muscle-skeletal system measures.

Do we have an idea of low the death rate of covid is when the vitamin D deficiency is fixed?

Just how much lower it would get cannot be discerned from available data yet. It is very hard to believe from current data that it would go all the way to zero and also very hard to believe that fixing all vitamin D deficiency would not save any lives. The confidence interval range in between is still large, but it is absolutely (past) time to act on the data because it is so unlikely to not help (or even not help a lot). And the data is so far consistent with the possibility that it could help so much that it would have reduced the pandemic to no worse than prior flu seasons had everyone's vitamin D been brought up above 30ng/ml before SARS-CoV-2 arrived.

I wonder if it correlates to Joe Rogan's fixation on Vitamin D

Steve Gibson has also been on the vit D train for some time predating covid.

As someone who first learned that healthy Vitamin D levels were known to decrease respiratory illness severity (regardless if they help with COVID) I have mixed feelings about the repeated front-page posts. On one hand, I think it's useful information to know. On the other hand, it starts feeling a little weird. Like that person you knew in high school who claimed that some marijuana product cured basically any illness. It feels like it makes it lose credibility.

Be careful not to conflated this letter with studies. If 142 letters were posted, I'd be right there with you. AFAIK(I haven't checked them all) the other links are mostly studies.

Shouldn't it be?