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Comment by mike503 | Hacker News Reader

Something I found interesting is that everyone thinks going outside and getting sunlight is simply vitamin D magic, this map seems close to what I remember seeing somewhere else which essentially says that a majority of the US doesn't have appropriate sun exposure to actually produce that reaction in a meaningful manner. (Note: I didn't read this link, I was just looking for a similar map)

https://www.health.harvard.edu/staying-healthy/time-for-more...

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There are apps which can track your vitamin d given a location and the times of day when you can produce vitamin d given the angle of the sun.

e.g. dminder https://play.google.com/store/apps/details?id=com.ontometric...

I've been using dminder religiously since reading an article about how chronically low everyone's vitamin D is which means sunscreen can be net harmful[1] and getting tested to confirm I was dangerously low.

I'm in Dallas, TX which has a reasonable window of about three hours in the middle of every day where the sun is high enough to shine a substantial amount of vitamin-D-producing UVB rays. Even so it takes conscious effort to schedule an hour outside in minimal clothing and it's hard to do when it's cold and doesn't work if the weather is overcast.

In the winter I'm only able to get vitamin D from sunlight maybe once a week.

Now I take vitamin D supplements[2] and I'm experimenting with UVB bulbs made for lizard terrariums.

1. https://www.outsideonline.com/health/wellness/sunscreen-sun-...

2. Vitamin D supplements are much cheaper if you get a pill maker, empty pill shells, and a bulk bag of vitamin D powder: about 5¢/50k IU pill which is a week's dose.

> get a pill maker, empty pill shells

Is this common? The only people I know doing that were making caps for recreational drugs.

I am in New Zealand, where caps appear to be available online for health supplements (I just did a quick search), so I’m guessing that purchasing caps doesn’t flag you in some system as a potential drug abuser.

>Is this common?

Among those that like to mess with supplements, yes. Buying something in bulk and filling your own pills in a purpose made tray is much more economical than buying bottles of them. At least as long as spending the time and dealing with the shitty mess that comes with such an activity.

Before your comment, I would have never considered that drug users would make use of it.

In the US, last I checked I believe there may be restrictions involved with the expensive automated machines though, because of the amount of what are essentially scammers mass producing bad supplements or just outright counterfeiting known brands. The efficacy of such restrictions is dubious at best, since most of the problem is going to be originating from outside the US anyways.

This seems a bit excessive.

Whole Foods has 365 vitamin D capsules in 1000 IU, 2000 IU and 5000 IU. Large bottle of 5000 IU comes out particularly cheap per dose.

How did everyone is scotland not die of Vitamin D deficiency?

My next opportunity for Vitamin D is next month!

Seattle checking in: my psychologist recommended 4000 IUs of vitamin D for me after the results of a blood test, and it's made a world of difference for the 9 months out of the year we don't nearly get enough sunlight.

Anecdote, sure, but checking this is something your general practitioner might not do on their own, so it's probably worth asking the next time you go in for a checkup.

Tacoman here: same, my doc put me on vitamin D after a blood test revealed a deficiency.

Also in Seattle and 4000 IU/day is the dose I landed at after testing my D levels, taking 2000/day for 6 months, and re-testing. 2k wasn’t enough, 4k was.

My doctor in the Seattle area said that over the years all her patients tested with moderate to severe deficiency except one.

I’m taking 5000 IU daily and it removed day sleepiness during winter months. Before taking it I would be just super sleepy during daytime.

One thing most people don't know is that how much vitamin D your skin produces depends highly on your skin color.

From memory, white skin produces 6x as much as black skin. This is probably the main reason for the white skin mutation, as we moved out of sun saturated Africa.

If you have dark skin, you very likely need vitamin D supplements if you don't live in a very sunny place.

Also sunscreen use, which blocks the UVB you need to produce vitamin D.

Worth noting that sunscreen only blocks a % of UVB, meaning you're still producing vitamin D while wearing sunscreen. Sometimes it's better for your skin to be wearing low SPF for regular sun exposure.

i.e. SPF 15, 30, & 50 sunscreen only blocks 93%, 97%, & 98% of UVB (respectively)

This is only in the winter that you can't produce vitamin D at high latitudes. The line drawn on that map you linked applies to the winter solstice, above that line there is at least one day where you don't make vitamin D.

Our bodies have the ability to accumulate enough vitamin D to make it through a long winter, if you are D replete before the days get too short. Depending on where you actually live, it is often just a few months that you don't make appreciable vitamin D.

If you compare Europe to North America, you will see that the population centers in Europe are shifted much further north, so you get a lot more chances for Vitamin D in the US vs most of Europe.

> This is only in the winter that you can't produce vitamin D at high latitudes. The line drawn on that map you linked applies to the winter solstice, above that line there is at least one day where you don't make vitamin D.

Also, worth taking into account is elevation; a +5000 ft elevation in Denver your skin receptors are not functioning the same way they are at in sea level Manhattan.

Hell, I try to make it to 10,000+ ft elevation in the Winter when I'm in CO in the Winter for this very reason (I'm from SoCal) that is below the 37th parallel where you can tan all year around.

My emphasis was on Vitamin D during my undergrad in biology, and while their has been some vitamin D exposure in the media every now nd ten, it's hardly what this hormone deserves and it's vital role in so many metabolic processes. The truth is that even it's erroneous classification goes to show how very little impact it has had in modern medicine despite a lengthy breadth of studies since at least the 70s on the topic tat sow its implications on Human physiology.

If people are really wanting to delve into this topic in earnest, as you should after COVID, this was my bible for my last 2 years of undergrad and something I always keep around to read [0]. Its out of print so it's costly, but chances are if you're familiar with SciHub you should be able to find it too.

As for US vs European production, mine is anecdotal but I know for sure my body was starting fall apart wen I was in the UK in the winter, it felt like my thyroid stopped working altogether: i was getting sick easily, I was sluggish and my mood was just despondent, it was really hard to get out of bed. I got tons of exercise and I was outdoors all the time, despite the floods happening that year (2014), so I could definitely tell a difference of being that far North at sea-level in the Winter.

0: https://www.amazon.com/s?i=stripbooks&rh=p_27%3ARoger+Bouill...

I have a UV index card I keep in my wallet (for no good reason). If you are receiving a UV index of 3 or higher on your skin, it is sufficient to induce endogenous production of vitamin D.

Now think how it is for us in Northern Europe. (And those in Alaska!)

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