That is doctoring on the symptom, not the cause.
Go outside. You do not only need Vitamin D, you also need fresh air, green and exercise. You can not get this with pills.
In the long run you save time, because of longer life (and hacking) and reduced illness (better hacking).
I thought it was funny that this blog post didn't mention getting outside as a potential solution. That said, it's not like it's a dichotomy: I take a daily vitamin D supplement, try to eat as much catfish and salmon as I can, and try to get out in the sun as much as possible.
That said, getting out in the sun is a fairly nuanced debate. Most dermatologists will tell you not to, because of the risk of skin cancer, and because of the lack of peer-reviewed research showing that the benefits of skin-based vitamin D production outweigh the potential for skin cancer:
Wearing sunscreen will inhibit vitamin D production, so getting some sun while wearing high-SPF sunscreen is not going to help you as much as unprotected exposure (per the dermatologist in the aforementioned article)
So the question becomes: do you believe the "vitamin D hypothesis" that vitamin D deficiency was the driving force behind the evolution of human skin color? The hypothesis is that northern Europeans evolved lower melanin levels in their skin through a combination of high latitudes and a diet deficient in natural sources of vitamin D:
So the question of whether you should go out in the sun (unprotected) in order to generate vitamin D becomes a question of whether you are more worried about the potential health complications of vitamin D deficiency or skin cancer.
Just an observation: there are certain time intervals in a day that you CAN get some sun exposure without worring (too much) about UV rays & skin cancer. I do not know about the rest of the world, but in tropical regions the intervals are 6-9 am and 4-6 pm. 15 minutes per day is enough in tropical regions and a bit more in other regions.
Nevertheless, you have more than a couple of hours to get outside and get some sun. Just have a schedule and stick to it :)
One last thing: visit your doctor often and check for overall nutrient levels (vitamins, minerals, etc) and avoid taking supplements before it.
I think most of us work at least partly during the day, and if you're at home. Sit near a window, works like sunscreen to keep keep your skin safe but still allows UV light below 350 nanometers which is all that's needed to produce vitamin D.
You don't get skin cancer like you get a tan, unless you're a vampire, or older.
Just go outside early in the morning or late afternoon, when UV levels are lower. Don't stay toasting on 12:00 PM sun like people going to the beach do. We're talking about 10-30 minutes of sun exposition here.
There are many different types of vitamin D synthesized in our bodies which require sunlight to form. The many varieties of D are used in an enormous amount of different chemical processes in our bodies- many of which are quite complex and not fully understood.
Vitamin D supplements consist of (mostly) one type of Vitamin D. People are typically deficient in that specific type so mild supplementation is a reasonable option. Just don't kid yourself into thinking that taking Vitamin D is a replacement for spending adequate time outdoors. Compared to the first 100 million years of our species existence, hiding indoors all day is a relatively new invention. It will be a while before science produces a silver bullet in gelcap form.
Could you provide some references? I'm really interested to learn more
EDIT: I'm looking for backup to the claim that sunlight provides something that you don't get in a vitamin D3 supplement. It seems reasonable but has a big impact on the solution.
[5] forms (vitamers) of vitamin D exist (see table). The two major forms are vitamin D2 or ergocalciferol, and vitamin D3 or cholecalciferol, vitamin D without a subscript refers to either D2 or D3 or both. These are known collectively as calciferol....Vitamin D3 (cholecalciferol) is produced by ultraviolet irradiation (UV) of its precursor 7-dehydrocholesterol. This molecule occurs naturally in the skin of animals and in milk. Vitamin D3 can be made by exposure of the skin to UV, or by exposing milk directly to UV (one commercial method).
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Vitamin D3 (cholecalciferol) is produced industrially by exposing 7-dehydrocholesterol to UVB light, followed by purification.[143] The 7-dehydrocholesterol is a natural substance in wool grease (lanolin) from sheep or other woolly animals. Vitamin D2 (ergocalciferol) is produced in a similar way using ergosterol from yeast or mushrooms as a starting material.[143]
Tl;dr of 5 types & only D2 and D3 are commercial avail
It looks to me like the supplement is D3 and the one you get from UV exposure is D3, so no, spending time outdoors doesn't give you any better Vitamin D than the supplement. Of course, exercise has other benefits.
I would amend that to no proven benefits. The body is a complex system. D3 generated by the body via natural pathways may be more effective than ingested D3 in some way we don't understand yet.
Leaving aside any other ill-understood benefits of sun exposure.
Also, Vitamin D is just one particular aspect our bodies depend on the sun. You also need sun exposition to improve the immune system, avoid depression and insomnia. Not to mention all the other biochemical processes and health benefits we still might not know.
The obvious fact is that we evolved to live under at least some sun exposition (depending on your genetic background), trying to replace that entirely with pills is backwards.
The above Factors are mostly regarding Vitamin D production or exposure onto your retinas. Nobody is claiming you need to replace it entirely. The right strategy depends on the context and esp. at which ends of the normal distribution curve you are (regarding sun exposure).
It's very seductive to argue from an evolutionary advantage perspective. It can be used to generate Hypotheses that need testing.
But one shouldn't give health advice based on it. After all we brush teeth, wear clothes and benefit massively from machines and modern medicine.
> It's very seductive to argue from an evolutionary advantage perspective. It can be used to generate Hypotheses that need testing. But one shouldn't give health advice based on it. After all we brush teeth, wear clothes and benefit massively from machines and modern medicine.
It's about sane defaults. The effort to validate every reasonable hypothesis is extraordinary, and sometimes impossible. We can't afford to live our lives based only on what conclusions science has been able to come to so far. Making some choices based on ancestral norms is perfectly acceptable and better than many alternatives.
Doesn't seam to be such a good heuristic, honestly. Why not look first at what seem to work for (a large sample of) other people?
Then you don't have to follow that complicated evolutionary logic style thinking. (I know it's very trendy right not)
In the end Nature isn't smart and can't think.
Vitamin D supplements are generally D3 by design because that's the form most readily absorbed by the body.
That said you're probably better off getting it from catfish or salmon (which also contain omega fatty acids, a "good" fat which you might otherwise consider supplementing if you aren't getting enough in your diet)
And of course it's not a dichotomy, you can supplement D3 daily and also try to eat a lot of fish!
Nitpicking, but I don't think we as a species have been here for 100 million years. I doubt we've been even as hairless as we are now for more than a few hundred thousand, so we may not have gotten as much sunlight due to that. But your point still stands.
I always wondered why the dogs always like to lay out in the sun and furred animals get their Vitamin D. Wikipedia: "In some animals, the presence of fur or feathers blocks the UV rays from reaching the skin. In birds and fur-bearing mammals, vitamin D is generated from the oily secretions of the skin deposited onto the feathers or fur and is obtained orally during grooming.[97]"
http://en.wikipedia.org/wiki/Vitamin_D
from personal experience, my computing sessions with reduced to no sunlight sessions for days in my room led to vitamin deficit, i did learn a lot of things though, but the results of the deficit are still apparent to me.
I supplement with 5000iu per day, and check my blood levels regularly. Even with supplementation far exceeding governmental recommendations, My blood levels have never exceeded 70 ng/mL, which is well within the health range of 30 - 100 ng/mL.
Here doctors look at you funny if you want to track biomarkers. "You're young, problems don't occur until you get old". As if they've never heard of prevention.
You can't blame them, that's in general a healthier attitude than obsessing over chemistry and stuffing yourself with pills. Same as full-body CT scans.
You do realize that our body keeps going via chemical processes? Genetics can cause insufficient absorption of certain nutrients, and given the long term consequences of chronic deficiencies, testing may not be such a bad idea after all. Also, knowing your blood work means that you won't be stuffing yourself with pills you don't need.
That's what I'm talking about :) 99% of people will go on to live just fine without knowing their precise blood levels. "Preventive medicine" is not considered to be advantageous, usually the anxiety and stress outweights any benefits unless you end up being the 0.1% and finding a serious condition that didn't raise any alarms in your body.
I was just going to ask if there are similar services in the UK. I'm assuming that we can't get this through the NHS, so does anybody know of any private services?
I think it's incorrect to use free health care as a "competitor" for this product. Here in Belgium (with free and awesome healthcare) people still pay for organic food, supplements, gym memberships and many other things to stay healthy.
So I would assume there would be a market for this too. I am speaking anecdotally though, like you.
They are competitors. Both do blood tests. It depends on how much your current healthcare provider would charge and what kinds of tests they'd run. They do the same thing (but possibly give you the results in a more enjoyable/easier to understand interface).
There will be quite some people that would pay more for better treatment/faster service. Or because doctors refuse the tests.
WellnessFx is a very neat idea. I wish they would allow you to get your own blood work and type in the results yourself and only charge for the analysis. Personalized medical advice would not be possible for plans like this - can't really trust the data, but at least you get some automated advice from the system, and your market could be the entire world not just three states.
And there are lots of posts here, with anecdotes and opinions... but nobody is talking about hard data, science, and (most importantly) clinical trials. Is that because it hasn't been proven through a real clinical trial that "programmers must take Vitamin D"?
The article says something too broad to be true (that if you're a programmer, you need to take vitamin D). However, a clinical trial would be overkill: you might need a clinical trial to determine if, say, cell phones are bad for you, but you don't need a clinical test to determine that 100% of people who stop breathing die. Where do you draw the line? Also, it spends a great deal of effort to make a statistically meaningful clinical test.
This could all be solved if, instead of prescribing supplements based on profession, the article's tone were more like "Hey, vitamin D defficiency is a thing and your lifestyle favors it. Go get yourself checked out and mention this to your doctor."
Of course there is a line to be drawn, but I think that dietary supplements certainly should be tested in clinical trials. Otherwise, there is no way to know if they work or not. This is typically how drugs/supplements are evaluated.
Sure, but clinically testing a supplement to see if it works is not the same thing as doing a clinical test to conclude that taking a "working" vitamin D supplement is good for you if you have vitamin D defficiency.
It really depends on (too) many factors. Out where I work and play, the problem is getting too much sun. An outdoor walk between my office and the lab at the other end of the building gets me plenty sun. Ditto the bike ride home (assuming I'm not working late on something). It also doesn't hurt that I get out to go hiking and climbing on a semi-regular basis. OTOH, if I worked for a startup in Seattle, yeah, I might need to up my intake of vitamin D (which I'm already taking in a multivitamin).
Of course, IANAMD, so the first thing I'd recommend is going to an actual MD if you have health issues - and mention your lifestyle.
It is pretty content-free, although I found interesting the claim that caffeine interferes with vitamin D uptake. I'll have to look into that (though the article included no references... ಠ_ಠ).
Most Americans are deficient in Vitamin D, programmer or not. [1].
One of the few supplements that are actually is a good idea, but don't overdo it, as it becomes toxic at higher levels.
You would not want to take more than 10 000IU per day and I'd probably recommend 2000IU-4000IU as a baseline. If you can afford the time and expense, the best is to close the loop and take a 25(OH)D blood test. You would want to have a serum level of between 30-70ng/mL. Given the studies I've read over a number of years I aim for around 55ng/mL, but there are differing views on this, so by all means do your own research.
This problem actually happened to me. A few years ago I started feeling incredibly lethargic. I would wake up with no energy. It was like sleep had done nothing for me. I didn't know what was wrong, but I felt horrible.
After around two weeks I went to the doctor. A blood test was done and it showed I had low vitamin D (26 ng/mL). After about a week of supplementation I felt normal again. It's easy to forget to go outside, and if you're a programmer and feel low energy, vitamin D is definitely something to look into.
20 is the lower limit of normal per US guidelines, though some specialty societies have their low threshold set at 30.
At any rate, you are unlikely to have any calcium metabolism deficits at 26 and it's unlikely to have been a cause of any symptom in an otherwise healthy adult.
Hrm, I may have the "ng/mL" part wrong then, or I may just be sensitive to low levels. All I remember is the number and that he said I was low. Supplementation definitely resolved my problems though.
26 ng/mL is not that bad actually... I once was tested at 12 ng/mL, and that was only after I asked for it when I fractured my left wrist for the second time in one year.
Personally I was so low down in D I also had neuropathic symptoms -- like your hand or parts of face falling asleep, light-headedness and muscle twitches and tremors. That all went even after some D vitamin injections.
But for the love of $DEITY, please wear adequate sun protection. At the very least that means a hat and sunscreen, but you probably want to be using long sleeved clothing and sunglasses if you're outside for an extended period of time.
Vitamin D deficiency is bad, but skin cancer is worse.
Vitamin D has anti-cancer effects which apply more generally than skin cancer. In studies which assess all-cause mortality relative to UV-B exposure, higher UV-B exposure is correlated with lower all-cause mortality. That is, more skin cancer yes, but also less death because of improved overall health and lower overall cancer risks. Importantly, this is not an endorsement of artificial tanning, which correlates with greater all-cause mortality. E.g.: http://www.ncbi.nlm.nih.gov/pubmed/21297041
"If you're fair skinned, experts say going outside for 10 minutes in the midday sun—in shorts and a tank top with no sunscreen—will give you enough radiation to produce about 10,000 international units of the vitamin."
You don't need a lot of sun exposure to get your body to produce enough vitamin D.
I started taking D3 last fall, and it has made a big difference in how I feel. I started with 3600IU for a few months and when I started feeling more energetic and cheerful dropped down to 2600 (2x 1000IU + 600IU & calcium). I get outside quite a bit, but in Vancouver WA the skies are overcast a lot and the low sun angle means you can't get enough for vitamin D needs. I also take a probiotic, an anti-oxidant, a fish oil and a green tea supplement. My diet is mostly paleo. My ancestry is northern European.
For reference, you need to take 50,000IU for several months to develop toxicity (ref: http://www.mayoclinic.com/health/vitamin-d-toxicity/AN02008). If you are pale skinned and don't spend a lot of time in the sun, you are much more likely to be deficient.
If you really want to see where you're at, have your doctor do a blood test, or go get a micro-nutrient test http://www.spectracell.com/mnt/
Taking supplements without assessing what your current daily intake of Vitamin D is can be dangerous; it is surprisingly easy to go over the recommended dosage, and there is such a thing as overdosing on vitamins [1]. You don't just get Vitamin D from the sun - it is also present in eggs, some seafood, and certain fortified dairy products. Because of this, you may not need to take a daily supplement at all. Programmers are at an increased risk for vitamin D deficiency, but you should ALWAYS examine your diet to assess your current vitamin D intake before deciding to take a supplement.
It's really, really hard to overdose on Vitamin D, and most researchers working on this have been taking much bigger doses than what's officially recommended. IIRC, some researchers were taking 10,000 IUs/day. Overdosing requires doses orders of magnitude bigger.
Those official levels were set to prevent people from getting rickets, NOT to prevent degenerative diseases or maintain optimum health.
In fact those official recommendations have been creeping upwards in a lot of places. Best would be to get a doctor to check your blood levels and supplement appropriately.
This will be a lot more accurate than assessing daily intake, since dose mainly correlates to time in the sun, which varies by location and time of day.
Well, I wouldn't say it's really hard to OD if one is not paying attention, although it's probably a very uncommon occurrence compared to deficiency rates. I have seen products with 50k IU available OTC and on the web, intended to be taken weekly.
One could see a scenario where this ends up getting consumed daily by mistake, and nutritionists would consider 50 000IU way to much in this case. (unless you have a specific condition, or post-op etc ad have been medicated in terms of therapy).
Try to find cases in the literature; you'll find cases of people taking orders of magnitude more than that for a month. But nothing serious from anyone taking 50k IUs/day, let alone per week.
I get your point that the studies are limited at such high doses, but Mayo clinic and various others disagree that it's non-toxic.
"Taking 50,000 international units (IU) a day of vitamin D for several months has been shown to cause toxicity" [1]
Regardless of that though, I agree that the UL is really difficult to quantify. Furthermore I'm not sure anyone could cite any article that shows a significant health benefit to supplementing above 10k vs below, hence, the rational choice would be to try stay below that.
However all of this talk about IU intake is secondary to the blood serum level. For the moment, that is the gold standard measure, until something something better comes along
Definitely agree with blood serum levels. In fact, I should get that done soon! :)
As far as really difficult, in Canada, ingesting enough pills to get to 50,000 IUs per day would be a chore. IIRC the last I checked the biggest OTC doses were 1,000 IUs. This might be different where you are.
Yeah it's definitely a good idea to inform yourself before popping a bunch of pills.
But, examining your diet is not going to help you make an informed decision in this particular instance. For example, you could have a gene that causes D malabsorption, or a specific type of gut bacteria that breaks down D3.
If you are serious about it, then a quick blood test is the best way to know. [1]
More importantly Vitamin D is tricky, because it has risks on BOTH side of the equation.
Deficiency can be very serious as well. Human biases tend towards non-action when confused or overwhelmed with information.
If anyone is interested in my data that has helped me, my blood tests are available on Google Docs[2] as well my 23andme partial genome[3]
Pretty much if you live in a northern part of the northern hemisphere (above 49 degrees latitude) you need a vitamin D supplement.
I recall reading about a researcher in Boston (I think) who said after about mid October you could be sprawled buck naked on a rooftop all day and not get enough vitamin D from (brief winter) sun exposure.
Vitamin D3 is very safe, one of the safer ones in fact. The target levels are still have a bit of controversy but safety is well documented. Taken blindly, without testing status, the conservative range is between 800iu to 2000iu daily. A weekly or monthly dose can be taken at once without issue.
I actually have to avoid Vitamin D. I have a disorder (Hypercalcaemia) that causes me to build up calcium in my blood. Vitamin D can rapidly improve the body's ability to absorb calcium (hence Vitamin D enriched milk). Too much calcium in your blood can lead to various physical nervous disorders (I get facial ticks in the muscles around my eyes) but can also result in various psychologically similar problems like depression, anxiety, insomnia, fatigue and various other problems. In severe cases can lead to coma and death as it can interfere with heart rhythms and other central nervous functions.
It's a real pain in the tail as the number of food products fortified with calcium and vitamin D is remarkably high.
Have you read much about vitamins K2 and A with reference to your condition? Supplementation or otherwise insuring adequate intake of K2/A might be of benefit for you in reducing vit D toxicity among other things.
How did you find out you have this? I've persistently had quite a few of the symptoms but nothing comes up on tests. In experimenting, I gave up all dairy which has helped a lot so I've simply been assuming I'm lactose intolerant..
Milk has a lot of other things which may trigger your allergies other than lactose. You might be lactose tolerant, but milk intolerant in general.
Furthermore, "Milk", quite surprisingly, is not well defined either. I've switched to RonnyBrook recently (NY local, organic, grass fed, and I get it within two days of leaving the cow), and it's a world of difference: The taste, my body's reaction (My lungs and sinuses would often respond to milk by clogging and excreting stuff, they don't anymore).
I haven't been able to find high quality sources (peer reviewed, etc) but I've read claims that the nutrient and vitamin profile of milk from grass fed vs. corn fed cows is completely different - which I don't really doubt - although I'm waiting for some high quality analysis for the exact difference.
Quite a few years ago I was suffering from lots of lethargy. I thought it might just be some kind of sleep apnea. A few blood tests showed an alarmingly high concentration of calcium in my blood which appeared to explain several secondary symptoms. I also have a family history of thyroid issues which is linked to it.
Cutting out vitamin d rich sources and most calcium rich sources had me back to normal within a few weeks. I'm back on calcium rich sources now without, much problem, but still need to watch for high vitamin d sources or the issues return.
I was tested and was deficient, now I take it every day and my levels are normal. Two buddies of mine got tested later and were also deficient, dangerously low even. We live in Portland, Oregon, so sunlight exposure is generally low, but I'd say it's a good idea for anyone to get tested.
I thought the evidence for the benefits of taking vitamin tablets (for anyone not deficient) was non-existent.
I'm also under the belief that diet modification works much better than vitamin tablets For deficiencies.
Blanket declarations that involve any form of medication is just wrong.
Sure alot of people don't get enough vitamin D and that may be more true in the feild of IT than others, but anybody who isolates themselfs and dosn't get out to grab a little bit of sun here and there will be a probably candidate for low vitamin D.
Now if you are one of those people who find themselfs driven to go take extra vitamins tthen you need to know a couple of things:
Vitamins are balanced in that you need one to enable another to do another thing and it's not as clear cut as dropping a few multi vits every day. It's better to com0liment your food intake with the occasional multi vitamin instead of a ritrual daily overdose turning your pee bright orange.
The other aspect is that if you are low on vitimin D and start taking supliments then you will get aches and pains which feel like your bones are bruised in places. DONT PANIC - this is a sighn that you were low on vitamin D and it is your body adjusting, it is normal and nothing to worry about beyond confirming you were low in that vitamin group.
But if you are that worried about lack of any vitamin then it is always best to compliment via dietary needs and for vitamin D you cant beat a nice walk outside at the right times.
Like any form of consumption be it vitamins, food, forum posts etc - the golden rule is moderation, moderation and moderation.
I took 10,000 ui a day for over a year to build my vit d level up to 176. I have multiple sclerosis. My goal is 200, have done a tone of research on the topic, toxicity levels, etc... For 12 years in a row, have had a relapse every winter, past winter didn't have one. One could say this is a coincedence, I say no.
In the summer I am always out in the sun alday, mostly every day, shorts, t-shirt, etc... For some reason, my body doesn't absorb the vit d good. I have fair skin, that tans very well. Anyways, I just wanted to share my knowledge to help others.
Well... I'm a web developer, not a "real" programmer, and I don't code at night. I did until I got married, but no longer. Now that I have a kid, it's suicide to do it more than once a week.
A high quality source of vitamin D is liver. Cod liver oil is a great way to supplement your diet. In Iceland you can get it in small sardine type cans and spread the liver on crackers.
It does contain some vitamin D, but it also contains about 10x as much vitamin A. Hypervitaminosis A is a real problem. I would not think it particularly safe to use cod liver oil for vitamin D supplementation because of this risk, especially when other supplements exist.
I always thought that mushrooms were a good source of vitamin D, ends up it a slightly different form and isn't a suitable source. Thanks for the heads up!
No one has mentioned reptile lamps yet? Medical UVB is expensive and probably can't be bought without a license of some sort. Reptile lamps you can buy from a local pet store or online.
But nothing beats the real sun (and greenery and fresh air), obviously. Given that the discovery of Vitamin D, heck the whole concept of vitamins even, is relatively recent, we really don't know what else we don't know.
I've been drinking recently a ridiculous amount of caffeine every day. (5-6 coffees + redbulls ) And at the same time I eat everyday tuna sandwich and salmons for dinner every third day. ( +snack a lot of bananas ). Regardless I've never been a real fan of this kind of food, so it must have been a natural body adaptation to low vitamins D level.
This is another anecdote point: my mom is a nutritional biochemist who has done research on vitamins for much of her life. She always tells me to take Vitamin D and that nearly everyone is deficient because we don't go outside enough (and live in high latitudes).
Not science, but the author is on to something, I think. If you doubt it, get your blood tested and see what your doctor says. If you don't want to get tested, take a conservative supplement.
I already take a basic multivitamin, but my concern is not that I'm trying to make a personal decision based on this article; I make my health decisions based on more research than that.
My concern is that the article makes a strong empirical claim that it does not back up:
>However, it also inhibits vitamin D receptors, and as such decreases the body’s uptake of this-much-needed-vitamin.
In fact, I can find a couple of studies sort of supporting this, but they have to do with a very specific vitamin D receptor in a very specific subpopulation (elderly women).
Some people are going to read this and they're going to assimilate into their "probably true facts" bank the idea that caffeine just generally keeps you from absorbing vitamin D, and then they're going to repeat that fact and it will spread, and we'll have a whole new common belief about caffeine which is probably false.
Does she have any take on B3 (niacin / niacinamide) you can share?
My own collection of anecdotes and understanding is that a nontrivial part of the western population is B3 deficient as well - not to the levels that cause pellagra to appear, but nevertheless way below optimal levels.
Also, from my collection of anecdotes and some reading, the most popular form of B3 sold these days (inositol hexanicotinate) is useless (0% bioavailability), which kind makes reporting and statistics unreliable, because it is actually confused with the available forms (which have different properties between them)
Every day at about lunch time I go lie on the roof in the sun for 10 minutes - doctor's orders. I also take D supplements but that alone was not enough to get my levels back to the normal range so I have to get some actual sun as often as I can too.
It's a bit of a 'damned if you do, damned if you don't' situation here in Australia: Approximately two in three Australians will be diagnosed with skin cancer before the age of 70, while approximately one out of three Australians have vitamin D deficiency...
You need to lay out during solar noon in the summer. In your 20s you can produce about 1k IU per minute for full body exposure, however, that goes down with age.
The sun's zenith has to be 45 degrees or higher in the sky for you to produce Vitamin D. A small spectrum of UVB (285 to 315 nm) is responsible for the subcutaneous photochemical synthesis of cholecalciferol, an important hormone of the endocrine system that we know as Vitamin D. Thus you want to avoid morning sun and late afternoon sun, and forget about it during the winter. So if your shadow is great than you are tall, avoid the sun.
You can google the time for solar noon in your local area. For example, in San Francisco, solar noon in for September 15th is 1:05 pm at which time the sun's zenith will only be 55 degrees. My runs in shorts and no shirt is soon coming to end for this season.
http://www.timeanddate.com/worldclock/astronomy.html?n=224
Regarding the 'damned if you do, damned if you don't' situation, don't worry about it. Melanoma is an office worker's disease, people who vocationally work outside have a higher risk of melanoma. Huh? Lower Vitamin D levels increases your risk of melanoma. Go figure, and sun screen block UVB, not UVA. So the rise in skin cancer might be due to increase in the use of sun screen, not sun exposure per se. More people get skin cancer, the more shrill the dermatologist become about using sun screen, and so the cat bites itself in the tail. More on that here:
How much supplements do you take? RDAs are in the range of 400-1000 IU, but apparently everyone I know who was actually tested and found deficient was asked to do 100mg/kg of body weight (meaning 7000-9000 IU), so it seems the RDA is off by an order of magnitude - perhaps established for a baseline of people who live in a sunny place and hang out a lot.
If you have dark skin you need more vitamin D, if you're obese you need more, if you're elderly you need more and if you are covered up in the sun you need more vitamin D.
7000 to 9000 IU sounds high but 1000 IU sounds way too low.
