Vitamin D and sunlight

[Blind groper]

Reference : New Scientist, 9 August 2014, page 37.

In recent years, we have all been inundated with the message to avoid too much direct sunlight, since it causes skin cancer. But consider this....

In the 1950's to 1970's, the people of Iran were very westernised, and wore western style clothing, exposing the skins to the sun. In 1979 came the Islamic Revolution. After that, both genders were required to cover up, and women to a ridiculous extent. Since 1979, the incidence of multiple sclerosis increased 9 fold!

The thing is that sunlight on human skin is needed to permit our bodies to manufacture vitamin D. Without sunlight, we tend to be derpived of that essential vitamin. According to the US Institute of Medicine, we need 15 micrograms per day. The only foods able to supply that much come from oily fish, such as cod liver oil. Scandinavians are likely the only people who get enough vitamin D in their diet, due to eating lots of oily fish. Other foods do not cut the mustard. For example, eggs are considered high in vitamin D, but you would need to consume 15 eggs per day to get enough. Fortified foods such as cereals are also too low. Vitamin D pills are an option, but it opens us to the dangers of overdose.

Sunlight on our skins is the only practical way for most of us to get enough vitamin D. Specifically, you need Ultra violet B. This means that people living in high latitude countries like Canada, especially if they have dark skins, are likely to suffer from the lack.

What does lack of vitamin D cause?
The best known problem is rickets, which softens bones. But even without rickets, people may end up with weaker bones, and more chance of fractures. Multiple sclerosis I mentioned, but it seems to apply to a range of auto immune disease also, including diabetes. However, a lack of vitamin D is also associated with a weaker immune system, and more infections from viruses and other pathogens. This may be why people get more ills in winter. Vitamin D lack is even implicated in a higher risk of cancer.

Vitamin D degrades in the body and needs to be replenished at least every two weeks.

What do you do?
Sunbeds are mainly UVA, not the required UVB. Do you take cod liver oil regularly, pop pills?

Are you paranoid about skin cancer and cover up too much? Do you hide indoors?

My view is that time outdoors is needed for mental health as well as vitamin D, and I spend lots of time in the sun, even in winter. But what do you choose?

[JimC]

My wife takes Vitamin D tablets regularly, after tests showed her levels were low. She has very fair skin, and avoids the sun with an almost vampire-like intensity...

[Svartalf]

I once broke my wrist after falling from a ridiculously low height, I suspect decalcification due to low vit D levels ... I'm no fan of the sun either.

[JimC]

I once broke my wrist after falling from a ridiculously low height, I suspect decalcification due to low vit D levels ... I'm no fan of the sun either.

You should get your levels checked...

[MiM]

Even though I have worked with radiation protection all my adult life, I still choose to move a lot in the sun in the summers. But obviously this is a case that requires moderation (both ways) if you want the best health benefits. Moderate amounts of sun is unquestionably good for you, too much is too much, and you should never let your skin burn.

Up here at Lat 60 a D-vitamin supplement is also needed during the dark and cold months. Use of sunbeds is discouraged by health professionals in the Nordic countries (except for special uses, eg treatment of psoriasis), and actually forbidden for kids under 18.

[PsychoSerenity]

I reckon I get enough in the summer. I'll usually be outside for a while at some point during the day, especially if it's sunny, even if it's only while walking to the shops or hanging washing on the line.

In the winter I just bask in the warm glow of my computer screen.

[Blind groper]

What do you think of the Iran islamic directive to cover up, leading to ill health?

[mistermack]

I like oily fish, but don't have it anywhere near often enough.

I might start keeping some pilchards in the fridge, to snack on once a day. Them and mackerel are my favourites, but mackerel these days are too small to be worth buying on a regular basis.
The bigger they are, the easier it is to deal with the bones. Any time they have big ones in stock, I stock up and cook them and freeze them. But it's getting rarer and rarer.
Maybe they are using finer nets these days, and catching them before they get to a decent size.
Shame.