While the headline is also true, the significance of this study (as the article explains) is showing that supplementation can reduce mortality. It was previously known that low blood levels of Vitamin D were linked to negative outcomes, but it was much less well agreed whether supplementing with Vitamin D would improve outcomes.
It's an obvious hypothesis, of course (low X associated with negative outcomes, so increasing X will improve outcomes), but not necessarily guaranteed: the low Vitamin D levels could've been symptoms of a different problem that isn't fixed by just supplementing with Vitamin D; or the supplements might've failed in various ways to be taken up or activate the right mechanisms.
An example of a similar obvious hypothesis that appears to be flawed: raising "good cholestrol" with niacin supplements appears not to lower risk of heart attacks as was widely assumed
The interesting thing about this study is the finding on a classic "hard endpoint," namely all-cause mortality. And what is worthwhile about this news story is that it doesn't just regurgitate a press release, but points out what issues haven't been resolved by the study. Those issues are always important to keep in mind.
appear to have some relevant experience and previous peer-reviewed publications. A finding of this nature must, of course, be replicated by other researchers.
Here is a link to the abstract of the e-publication ahead of print of the underlying study in the American Journal of Cardiology:
It might be worth considering at any latitude; despite the association with sunlight, the NIH notes that "perhaps surprisingly, geographic latitude does not consistently predict average serum 25(OH)D levels in a population". (http://ods.od.nih.gov/factsheets/vitamind)
Get your levels measured and dose accordingly. Most people are deficient in a number of areas, and you can get screened for them all at once.
In the absence of that, if you're just making a qualified guess, you should probably dose significantly more than 1,000-2,000 IUs/day. The daily intake required for toxicity to be an issue are very high (sustained total intake of around 20,000 IUs/day). It's also generally recommended that D3 supplements are taken alongside a K2 supplement.
Talk to your doctor. They can take a blood test and send it off to analysis. It can be somewhat expensive. When I said "all at once" I didn't mean that a simple biochemical test can reveal all deficiencies, obviously, but that a single blood test can be sent off to have many different tests done. I'm not yet sure exactly how it works in the US, sorry.
The kind of deficiencies I had in mind would be vitamin (e.g. D, K), mineral (e.g. iron, calcium) and electolytic (e.g. magnesium, potassium).
About two years ago CBC news had a great segment on vitamin D and cancer rates.
Anyone in northern (far south) climate isn't exposed to enough sunlight after early Fall.
Even if you were outside naked all day you'd never get enough sunlight to make enough vitamin D. It's even worse if you have a naturally dark complexion .
I have personally found vitamin D supplementation to help with my mood and energy level, at least in winter.
If you get a lot of sun on a summer day, your body can make as much as 10kIU. So supplementing at the level of around 1kIU/day, which is what I do, seems reasonable.
A friend on mine who has Multiple Sclerosis mentioned to me that it gets much worse for him in the winter, and then gets better heading into the spring and summer. IIRC low vitamin D is believed to make MS worse. He was going to try tanning beds this winter to see if it helps (usually tanning beds are bad news due to cancer risk, but in his medical case his doctor recommended it). Disclaimer: All anecdotical.
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Vitamin D is synthesized by your skin from sunlight using UVB rays. This is interesting to note, indicating that being far from the equator does not mean you cannot get enough UVB rays from sunlight during the winter:
The assumption that vitamin D levels in the population follow a latitude gradient is especially questionable in view of surveys which have shown that UVB penetrating to the earth's surface over 24 hours during the summer months in northern Canada equals or exceeds UVB penetration at the equator. Accordingly, there is sufficient opportunity during the spring, summer, and fall months at high latitude for humans to form and store vitamin D3.
Perhaps if true, that means when it's cold out people stay indoors and wear lots of clothing when outside, effectively limiting sunlight exposure, meaning less vitamin D production in the winter...
Living in the southern hemisphere (the one with the bigger ozone hole) and being an import from dark cold places I turn into a lobster with moderate sun exposure. It doesn't always get better heading away from the equator here due to ozone depletion.
Adding computers, air conditioned comfort and a complete disinterest in outdoor activities to the mix and I doubt if I get enough vitamin D to last me through the winter. Skin cancer avoidance is well understood here and drilled into kids from pre-school age but lifestyle changes may be putting some people into other risk areas.
Curiously, I have a skin condition that is treatable by UV exposure, topical vitamin D analogues and generally improves in summer yet as far as I know there is no clinical evidence that vitamin D supplements have any benefit.
D-deficiency also nearly doubled a person's likelihood of dying, whereas correcting the deficiency with supplements lowered their risk of death by 60 percent.
Damn, and I thought that risk was at around 100%...
The studies I've seen have shown have very different numbers, and show that our bodies are very good at dealing with lots of Vitamin D but very bad at dealing with too little. From what I know, there is no known negative side effects under about 14,000 UI a day, and based on blood tests, Dr. William Davis, a cardiologist, has been recommending amounts in the range of what I take (even a bit higher). The official recommendations have been too low for a long time.
Is there an OTC kit for testing vitamin D levels? ("Serum concentration of 25(OH)D is the best indicator of vitamin D")
Can someone make one of those nifty little bio-chip things (do those exist?) that is connected to a little needle thing like electronic insulin monitors?
There are companies that sell kits where you collect a blood sample at home, and then mail it in for analysis (except in NY, which apparently bans medical tests by mail).
Not to be the correlation/causation asshole, but I wonder if possibly low vitamin D is to some extent a proxy for being a low income sedentary shut-in, all things that on their own are tied to disease.
As the article points out Vitamin D supplementation is not very effective vice working up a tan a couple times a year. So in modern America we can surmise the individual with low vitamin D levels is someone who sits inside watching TV all year. And can't afford a winter vacation to somewhere sunny.
Is the problem low vitamin D, or is it being sedentary inside all year? It's probably actually the vitamin D.
Weird question: say you were only awake at night and therefore had very low blood serum levels of Vitamin D. Would drinking a healthy person's blood improve your own Vitamin D levels?
Probably not by a significant enough level that you wouldn't have problems from iron overload first. Vitamin D blood levels are measured in picograms or nanograms per mL. You need more like a milligram or so per day.
It's an obvious hypothesis, of course (low X associated with negative outcomes, so increasing X will improve outcomes), but not necessarily guaranteed: the low Vitamin D levels could've been symptoms of a different problem that isn't fixed by just supplementing with Vitamin D; or the supplements might've failed in various ways to be taken up or activate the right mechanisms.