[Kevan Gelling]

Kevan Gelling asked the Naked Scientists:
   
Chris,

HPV causes cervical cancer; childhood diabetes has been linked to a virus; research this week has identified mutated DNA in pancreatic cancer; genome research has shown that viruses alter our DNA.

Vitamin D is linked to many illnesses (including the ones above), although it is not known how.  What if Vitamin D's main function is to kill viruses?  What if all illnesses linked to Vitamin D are caused by viruses?

In other words, low Vitamin D leads to more viral infections which can cause DNA mutations which in turn can cause cancers, diabetes and other illnesses.
 
List all illnesses linked to Vitamin D and we get a list of illnesses caused by viruses and we can then look for the virus(es) at fault and hopefully make vaccines to prevent it.

Is this possible?

Thanks
Kevan Gelling

What do you think?

[Bored chemist]

"Vitamin D is linked many illnesses (including the ones above), "
By whom?
Anyway, since most of us have plenty of vitamin D but still get viral infections from time to time, the answer to the title question is "No".

[Kevan Gelling]

Here are the new stories:

• Diabetes + Virus
• Pancreatic cancer + mutated DNA

Here are some Vitamin D research links:

• Diabetes (PubMed - Vitamin D supplementation in early childhood and risk of type 1 diabetes: a systematic review and meta-analysis.)
  
• Multiple sclerosis (PubMed - The causal cascade to multiple sclerosis: a model for MS pathogenesis)

• Heart disease (PubMed - Vitamin D deficiency and risk of cardiovascular disease
• Parkinson's (PubMed - Prevalence of vitamin d insufficiency in patients with Parkinson disease and Alzheimer disease)

And there's plenty more - look on PubMed or Vitamin D Council. I'm not able to assess whether the quality of the research, but there's lot of it.

Regards,
Kevan

[Bored chemist]

Since most of us have plenty of vitamin D but still get viral infections from time to time, the answer to the title question is still "No".

[Variola]

Vitamin D is linked to many illnesses (including the ones above), although it is not known how.  What if Vitamin D's main function is to kill viruses?  What if all illnesses linked to Vitamin D are caused by viruses?

In other words, low Vitamin D leads to more viral infections which can cause DNA mutations which in turn can cause cancers, diabetes and other illnesses.

Thats actually quite an interesting question, its made me ponder.

 There is no evidence ( that I have found throught trawling ) that vit D kills viruses, I wish that it did!

The problem is that not all viruses will causes DNA mutations. those that might cause it, might cause it in some people but not others, or may cause different mutations, or the right collection of mutations may not be present in some people but are in others depending on previous infections etc etc the list of permutations goes on.  Cancer itself usually has at least 6 mutations present on a cellular level. Like a lot of microbiology its lots of if's and but's and might be's.

I'm still reading the links you have posted ( they have lead me onto other articles!) but I will continue mooching roud pubmed, web of science etc see if I can dig anything else up.

[wolfekeeper]

I don't think vitamin D kills viruses. It probably has a modulating effect on the immune system though; if you are deficient in vitamin D then many human systems won't work as well, and the immune system is doubtless one of them.

[Bored chemist]

"Hi B.C.
Citation/source/reference...please."

I didn't see anyone with rickets today, did you?.
Also, with the huge variation in human diets there would be some people who positively rattle with vitamin D. If they were immune to viral infections someone would have noticed.

Incidentally while all this stuff about vitamin D being some "cure all" is entirely speculative, the real evidence of what lots of vitamin D does results in the stuff being used as a rat poison.

It would be a shame if some misguided person saw this thread and poisoned themself with vitamin D because they thought it might cure the common cold.

[wolfekeeper]

It's for all practical purposes impossible to do this accidentally, I'm pretty sure that there's never been a vitamin D poisoning case that doesn't involve an industrial accident or taking wayyyyy too many prescription strength pills over a loooong period. (There was a batch of vitamin pills that were made 100x too strong, a few people got ill).

Most people could take about 100 vitamin pills a day for several months before reaching toxicity levels.

If you go out in the sun for about 10 minutes your skin produces maybe 20,000 IU; the average pill has about 200-400 IU in it, dietary sources are much lower. Skin self limits, but pills don't. But I think the studies seem to say you can take up to about ~20,000 IU without any known long term harm at all. I think about 100,000 IU/day would put you in hospital... eventually.

Only a few food sources (mainly oily fish) give only a few hundred IU per portion, and most foods give none at all. There's only about a dozen common foods that have any significant vitamin D in at all. Eggs, 20 IU, you would have to eat 5 eggs a day to get up to your daily requirement.

[iko]

If you go out in the sun for about 10 minutes your skin produces maybe 20,000 IU; the average pill has about 200-400 IU in it, dietary sources are much lower. Skin self limits, but pills don't. But I think the studies seem to say you can take up to about ~20,000 IU without any known long term harm at all. I think about 100,000 IU/day would put you in hospital... eventually.

Only a few food sources (mainly oily fish) give only a few hundred IU per portion, and most foods give none at all. There's only about a dozen common foods that have any significant vitamin D in at all. Eggs, 20 IU, you would have to eat 5 eggs a day to get up to your daily requirement.

Hi wolfekeeper,

I agree with you.
Vitamin D is not a 'real' vitamin, a cofactor that you get from your diet.
It is a steroid hormone, produced by our skin through sunlight exposure.
Difficult to measure (nanograms per mL in the circulating blood), it's coming late as a wonderful agent, able to control the function of over 200 genes.
Recent research results are quite promising, and its anti-infective properties (through antibiotic peptides production) have been defined only 4-5 years ago.
The old cod liver oil given to TB patients in the last century is finally scientifically proven as a treatment support!

[Bored chemist]

Can I cite Wolfekeeper's post as evidence that most of us get enough vitamin D?
"If you go out in the sun for about 10 minutes your skin produces maybe 20,000 IU; the average pill has about 200-400 IU in it, dietary sources are much lower. "
So it's easy to get, at least in the Summer, yet people get viral diseases during Summer (perhaps fewer than Winter but that's
1 due to confounding variables and
2 not the point; if vit D killed viruses then practically nobody should get a viral disease in Summer.)
Vitamin D doesn't kill viruses no matter how nice it would be if it did.

[iko]

"Hi B.C.
Citation/source/reference...please."

I didn't see anyone with rickets today, did you?.
Also, with the huge variation in human diets there would be some people who positively rattle with vitamin D. If they were immune to viral infections someone would have noticed.

Rickets is still around: I've seen children, I read reported cases:

http://content.nejm.org/cgi/content/extract/360/4/398
http://www.uvadvantage.org/portals/0/pres/

BTW, where is your citation about "...most of us have plenty of vitamin D"?

iko

[wolfekeeper]

Can I cite Wolfekeeper's post as evidence that most of us get enough vitamin D?
"If you go out in the sun for about 10 minutes your skin produces maybe 20,000 IU; the average pill has about 200-400 IU in it, dietary sources are much lower. "
So it's easy to get, at least in the Summer

Actually, a lot of people seem to be deficient if anything. Note that's only about enough for 100 days of the RDA (and there is a case that the RDA is too low BTW.)

There's also issues in that the exposure has to be over most of your skin with the sun high in the sky to make anything like that much, and a lot of Europe is quite a long way North.

[Bored chemist]

Only 10 minutes sun in 100 days is a bad Summer, even by British standards.

[wolfekeeper]

Yeah, but it saturates, so if you haven't seen the sun in a hundred days, you're risking deficiency, so over winter is particularly bad. And note that it's the UV-B that's important, which is mostly a midsummer thing.

Right about now it would be likely to be particularly low, or a month ago maybe.

[Bored chemist]

OK, but people do still get viral infections in the height of Summer.
I only need to find one sun lover with a viral infection to show that vitamin D doesn't (reliably) kill viruses.
How about my Aunt? She lives in South Africa, hates the cold, loves the sun and got shingles.
Now that's a virus she picked up as a child (ie chickenpox). So for decades she had plenty of sunshine (much of it before there was an association with cancer) and so she would have had about as much vitamin D as anyone gets and, in spite of this, the virus lived for those decades.

At least one virus is not killed by vitamin D.

Incidentally, my guess is that more viruses are "killed" by sunlight than by any other cause, so there's an interesting problem with that confounding variable in this discussion.

[wolfekeeper]

Actually, if anything, as I understand it, vitamin D tends to suppress the immune system.

But, yes, sunlight itself is a good antibacterial, antiviral and antifungal.

[Kevan Gelling]

Since most of us have plenty of vitamin D but still get viral infections from time to time,
the answer to the title question is still "No".

Your reasoning is poor.  Using this logic I could state - Since most of us have plenty of white blood cells but still get viral infections from time to time, the answer to "Could white blood cells kill viruses?" is still "No".

Is there scientific evidence (rather than conjecture) that links high levels of Vitamin D with low levels of viral infections? "Yes" - Epidemic influenza and vitamin D

A couple of other points:
* The sun is not strong enough in the UK (above 50N latitude) for the skin to make enough Vitamin D for most of the winter (Daniel E. Roth DE, et al. Vitamin D insufficiency is common in Canadian children and adolescents: national guidelines provide insufficient vitamin D to maintain adequate blood levels. Can J Public Health 2005)
* Vitamin D deficiency be found in the sunniest places - Vitamin D deficiency in Sydney skin cancer patients

[Bored chemist]

My logic is fine; you just haven't understood what "plenty of" means.
Unlike vitamin D, the body makes lots more active white blood cells during infections It can't make lots of vitamin D.

A couple of repeated points
"The sun is not strong enough in the UK (above 50N latitude) for the skin to make enough Vitamin D for most of the winter " And people get viral infections in Summer.


"Vitamin D deficiency be found in the sunniest places - Vitamin D deficiency in Sydney skin cancer patients"
Since most of us have plenty of vitamin D but still get viral infections from time to time...

[Kevan Gelling]

My logic is fine

Your logic:

• (plenty of X) AND (get viral infections) INFERS (X cannot kill viruses)
• IF X = (white blood cells) THEN (white blood cells cannot kill viruses)

Hmm

[Bored chemist]

Please chack the meaning of the word "infer".
Also, I think that white blood cells don't technically kill viruses. They kill viruses that have been tagged by antibodies.
In the absense of those antibodies then that logic is true (provided that you swap the word "implies" for "infers")
On their own neither white blood cells nor vitamin D kills viruses. With help the cells can do it.
What provides the putative help for the vitamin?

Anyway, why didn't the vitamin D kill my aunt's chickenpox virus?