Lack of Sunlight Could Lead To Early Death 304
I Don't Believe in Imaginary Property writes "Members of this community may want to venture out of the basement more often, because Dr. Harald Dobnig and his team have found that vitamin D deficiency leads to increased mortality. These results still hold when they take into account such factors as exercise and heart disease. Low vitamin D status has 'other significant negative effects in terms of incidence of cancer, stroke, sudden cardiac death and death of heart failure,' Dr. Dobnig said. The evidence of ill effects from low vitamin D 'is just becoming overwhelming at this point.' Vitamin D3 is usually produced by exposure to the UV-B in sunlight, but in high latitudes, especially in the fall and winter, insufficient UV-B gets through the atmosphere to produce enough vitamin D3, even with hours of exposure. The researchers are recommending that people at risk for deficiency take 800 IU of vitamin D3 daily. Just don't go overboard — as a fat-soluble vitamin, D3 is more capable of causing adverse effects at unnaturally high dosages. The human body tops out at producing about 10,000 IU per day." According to the Wikipedia entry linked above, the D2 (ergocalciferol) version -- available as a vegan product -- works approximately as well to supply humans with their needed vitamin D.
UVB CPF anyone? (Score:5, Informative)
Re:Sunlight (Score:5, Informative)
Actually all the studies that address "too much" involved sever sunburns in teen years.
There is no peer reviewed study that suggests normal exposure to sun imposes a high mortality.
Yet the press, over-reacting as usual, have scared people out of the sun and created a sunscreen industry overnight by failing to actually read the studies that were done.
Cancer rates caused by sun exposure only show significant rise in direct relation to bad burns. Avoid the bad burns and you are fine.
60 thousand years of human existence can't be discounted overnight.
Go out and play. Get a tan. Drink some coffee. Have some beer with those salty chips. Lets see, did I forget any of the other discredited cancer scares?
Re:Sunlight (Score:5, Informative)
Cancer is only one potential risk. The sun worshipers I've known still are wrinkled way beyond their years.
Vitamin D and auto-immune diseases (Score:3, Informative)
Re:Sunlight (Score:5, Informative)
Re:Bullshit (Score:3, Informative)
We sometimes have entire months here in Ireland with little direct sunshine (I think last year some places had an entire 80 day block with rain each day, and that was in the lousy summer we had last year).
In any case, it's not a matter of the amount of light in winter. It is to do with UVB rays, and these don't reach us in the winter due to the sun being low in the horizon and refraction from the rays passing through more atmosphere. Not only that, but even past the height of winter, these rays only reach us when the sun is higher in the sky (the middle of the day).
Careful with too much Vit D (Score:5, Informative)
Disclaimer: IAAJD (I am a junior doctor) but this is NOT medical advice. Please consult your physician for your specific situation.
Vitamin D supplements come in two forms: ergocalciferol and cholecalciferol. Studies suggest that cholecalciferol (vitamin D3) increases serum 25-hydroxyvitamin D (25-OH-D) more efficiently than does ergocalciferol (vitamin D2). Milk in the United States has been fortified with vitamin D3 (the natural form made through sunlight) since the 1940. This was mandated and reduced the incidence rate of juvenile rickets by 85% in the United States.
Calcitriol is the most active metabolite of vitamin D. It can frequently cause hypercalcemia and/or hypercalciuria, necessitating close monitoring and adjustment of calcium intake and calcitriol dose. Therefore, it isn't recommended that calcitriol be given for vitamin D supplementation in osteoporosis. However, calcitriol or other vitamin D analogs are an important component of therapy for secondary hyperparathyroidism in chronic kidney disease.
Now to the meat and potatoes of this post. The intake at which the dose of vitamin D becomes toxic is not clear. In 1997, the National Academy of Sciences defined the Safe Upper Limit for vitamin D as 2000 IU/day. Newer data however indicate that higher doses are safe at least over a several-month period. Doses as high as 10,000 IU per day for up to five months were not associated with toxicity. It is important to inquire about additional dietary supplements (some of which contain vitamin D) that patients may be taking before prescribing extra vitamin D. Excessive vitamin D, especially combined with calcium supplementation may cause hypercalcemia, hypercalciuria, and kidney stones.
So be careful and only take the amounts listed on your supplement bottles and inquire with your doctor before starting anything. We have a mentality here in the United States that more is better. When it comes to the human body moderation is key.
As a side note, I also don't really understand the significance of Vitamin D's fat solubility making it any more or less dangerous in higher dosages.
Crash course in Vitamin D (Score:5, Informative)
Vitamin D is produced by the skin in response to certain wavelengths of ultraviolet light, and as such is not a true vitamin (since vitamins are substances we can't naturally produce -- it's a hormone). Vitamin D is also found in certain fats (e.g. cod-liver oil).
This basic form of Vitamin D gets processed by the liver into an second form (25-hydroxyvitamin D3), and then by the kidneys into the active form 1,25-dihydroxyvitamin D3, which tells your body how much calcium to draw out of your food. If you don't have enough calcium in your diet, but enough Vitamin D, the body can even draw the calcium out of your bones. Calcium is also required for the correct transmission of brain signals, so too little vitamin D can also lead to seizures.
To veer back to the OP's question: whether the synthetic vitamin D additive to milk products (as opposed to the vitamin D we used to create in foods in the 1920's and 1930's using mecury lamp ultraviolet radiation) is Vitamin D or Vitamin D3 is pretty much irrelevant for our body, but I believe it is the latter, yes.
Aside: Did you know we can cure cancer with Vitamin D? Sadly, the dosis required is lethal to humans... they're working on it.
Fat soluble vs. water soluble (Score:4, Informative)
Disclaimer: I'm not even a little bit of a doctor, so this might be completely wrong or misremembered...
Re:Sunlight (Score:5, Informative)
Re:Fat soluble vs. water soluble (Score:2, Informative)
OP is correct. fat soluble vitamins such as A, E are stored in cells and can be very toxic. water soluble vitamins, although easily flushed from the body, can still cause several diseases. there is no significant difference in how easy or difficult a vitamin builds up concentration. it comes down to the bodies ability to metabolize substances.
there are far tighter levels on water soluble vitamin overdose levels than fat soluble. it also logically follows that fatter people can take more into their cells than a skinnier person. this isn't a factor with water soluble vitamins. good on the OP for being astute to the error in the summary.
wikipedia overdose link [wikipedia.org]
Re:Sunlight (Score:2, Informative)
The original publication is here [nih.gov]. Honestly I wonder why we did not see any follow up untill now.
In case you like to read: #18565885 [nih.gov], 18424428 [nih.gov] and 17540555 [nih.gov]
(no open access, I'm afraid).
Re:Careful with too much Vit D (Score:2, Informative)
I'm the OP.
There are several reasons to repeat the study. The issue in the 1940's was rickets but today we're seeing an increasing number of diseases such as "cancer, stroke, sudden cardiac death and death of heart failure" with Vitamin D playing a factor. We would be arrogant as doctors to assume we know everything so this deserves further investigation. Furthermore, the ill effects of years of media scare stories of the sun's "harmful rays" has lead people to put on sunscreen when they reluctantly go out.
The article mentions that nearly half the elderly population in the United States has low Vitamin D. This isn't surprising because they rarely go out due to the ravages of aging. Children, though, as also being seen with increasingly low levels of Vitamin D--probably having a lot to do with parents insisting children not play outside due to safety issues and also caking them over with sunscreen. Until these issues are publicized and new protocols issued on the standard of care, these studies will be necessary. Going outside isn't the only solution but its far better than just drinking more milk. We must start focusing very heavily on easily modifiable variables so we can prevent diseases in tomorrow's aging population.
Re:Milk as subsitute? (Score:2, Informative)
Milk doesn't provide enough to make a significant contribution. In the US, almost all milk sold commercially has been fortified with 400 IU of D3 per quart.
Your skin will make up to 10,000 IU per day, *if* you get 10-15 minutes of direct sunlight. Your body's ability to do that diminishes with age.
In April, my doctor had me take a 25-hydroxy D3 test (which Blue Cross refused to pay for, BTW), and found that my level was 19.5 ng/mL. Recent studies show that 32 ng/mL is a minimum threshold for good health (Hollis, J Nutr. 2005 Feb; 135(2); 317-22). He prescribed a series of 50,000 IU capsules, one every 4 days.
I might point out that I'm a cyclist--I get plenty of sun in the summer--but I am over 50.
Also, good luck trying to find 50,000 IU D3 capsules in any store.
Anyway, here are some interesting articles:
http://www.vitamindcouncil.org/ [vitamindcouncil.org]
For the conspiracy-minded among you, there has been a proposal on the table to increase the MDI, but the pharmaceutical companies don't want the recommendation adopted until they have developed some patentable analogues.
Re:Sunlight (Score:5, Informative)
Don't fall for the error in statistics that cause human lifespans to seem short before modern times -- average lifespans were short because of massive infant mortality, not because people who survived to be adults didn't live to old ages.
There's no evidence to suggest people died earlier 5,000 or 50,000 years ago -- and there's strong counter evidence for that during historical periods of the last 3-5k years.
Re:Sunlight (Score:1, Informative)
hell, half the people who died before 1920 all have "died of a sudden" on their certificates. We just didn't know what the hell they died from, heart attack, fart attack, cancer, whatever. With new diagnostic tools and a penchant for autopsy, we're figuring out a lot more these days.
Lifespan (Score:5, Informative)
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The best way is to look at the median lifespan - the age to which 50% of people reached or to look at life expectancy at age 20. Life expectancy at 20 didn't reach the 60's till the last century. There were certainly some lucky people who survived to age 70 or 80, but that was the exception rather than the rule. However the biggest gains in life expectancy in the modern era weren't because of level 1 trauma centers and ICUs. The big improvements were due to things like public sanitation, improved nutrition, vaccinations, refrigeration, and simple prenatal and antenatal care.
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Hobbes was right: life in the state of nature is "nasty, brutish and short".
Re:Careful with too much Vit D (Score:1, Informative)
I also don't really understand the significance of Vitamin D's fat solubility making it any more or less dangerous in higher dosages.
Re:Sunlight (Score:2, Informative)
Wow...every doctor (including dermatologists) I've ever been to would seriously disagree. The "press" has nothing to do with that. The best you'll get from a "healthy tan" is skin that looks like an old football by the time you're 45...the worst you get is dead.
As someone whose father (who spent WWII in the tropics) and has been battling various carcinomas his entire adult life, and whose grandfather (who worked outdoors a lot) died from melanoma, and whose best friends father (an avid golfer) is in the process of dying from one...I have to ask you where on earth you got this from?
Re:Sunlight (Score:4, Informative)
Just go outside for 10 minutes every day. It's not that bad.
It was crappier (Score:3, Informative)
Actually, we have better statistics than that. Say, from the Egyptians, we have plenty of records left of when someone died. You know, plaques, inscriptions, etc. So you have a somewhat random sample, and the ages at which they died.
So you can sorta plot a gauss curve, albeit one with a massive spike in the first 3 years, due to the infant mortality that you mention. But the more interesting part is what happens when you look past that spike, at the peak of the proper gauss curve. That's basically the age where, if you survived those infant years, you'd have a 50%-50% chance to be dead anyway.
And for the Old Kingdom period (i.e., a bit over 4000 years ago) that peak was in the 30's for men and in the 20's for women. By the New Kingdom (a bit over 3000 years ago), it had progressed to 40's and respectively 30's.
So, yes, they did live less. Seriously. Yes, there was massive infant mortality, but, no, you can't dismiss everything based on just that.
Yes, like with anything statistical, there were exceptions in both directions. There were the occasional guys who lived very long lives, but they were the exceptions, not the rule. They also tended to be the rather rich guys.
And I think one funny thing that may have helped confuse people about life expectancy back then, is the egyptian expression that someone lived to 110 years old. It's funny because it's just a metaphor. In their numerology, 110 was the perfect number, and they believed it to be also the absolute maximum someone can live, if they led a perfect life. So "he lived to 110", was basically just a way to say, "he lived a perfect life." Meaning typically that he was really well liked guy in the community. In practice most of those were dead in their 30's and 40's.
Basically it's just as much a metaphor as when we say that someone was born with a silver spoon in his mouth, or jumped the shark, or put his foot in his mouth, or the like. We don't mean it literally, and it's silly to build biological explanation based on it.
Re:Worse in northern hemisphere (Score:3, Informative)
Actually, there are two important forms of skin cancer: basal cell carcinoma and malignant melanoma. The differences between these two forms of cancer are so significant as to be "critical knowledge for humans", and yet they tend to be lumped together under "skin cancer".
Basal cell carcinomas are pretty low grade, tend to be very easy to treat, and are not associated with very many mortalities. They are unlikely to metastasize (spread) and don't grow very quickly. Basal cell carcinomas are associated with repeated mild sun exposure, so getting out in the sun and tanning increases your risk of basal cell carcinoma. This is also the most common form of skin cancer by a long stretch.
Malignant melanomas tend to be higher grade cancers, are much more likely to metastasize, and are responsible for most of the mortalities from skin cancer. Malignant melanomas are associated with extreme sun exposure, so staying out in the sun too long and getting a severe sunburn increases your risk of malignant melanoma.
So once you discriminate between kinds of skin cancer, there's a strong case to be made that tanning is a low risk activity, while burning is a high risk activity. Further, as this study showed, levels of vitamin D are inversely associated with malignant melanoma, and vitamin D is naturally produced through repeated mild sun exposure without sunscreen (sunscreen blocks the UVB needed to endogenously synthesize vitamin D3).
So, being in the sun without sunscreen long enough to get a tan but not to burn is not only low risk, but actually reduces your overall risk of dying from cancer.
There are other benefits to regular exposure to direct sunlight. It can help with mild depression, sleep disorders, eye problems, and a whole host of other benefits. Tough to get all of that in a one-a-day vitamin (joking, vitamin D that's not suspected in oil is only marginally bioavailable, so if you're not taking a vitamin tablet and you're not going outside, you're not actually getting any vitamin D).
Besides, is getting outside for 15-20 minutes a day really that tough? Go for a walk for chrissakes.