After living with vitamin D deficiency for the past 50,000 years we’ve finally woken up to how serious the problem is – the BBC has started reporting the issue. Unless you’ve been living in a hermetically sealed envelope the last few weeks, you’ll be aware that vitamin D is the nutrient du jour. Cases of childhood rickets – a sign of severe deficiency – have rocketed over the last 15 years with one in four toddlers thought to be at risk.
The problem can be traced back to the Garden of Eden, and our leaving thereof. That’ll teach us to go seeking knowledge. Humans originated in equatorial Africa, where we all went about naked as newborns, enjoying year-round warm sunshine and vitamin D on tap. We also all had black skins that offered protection from the blazing sun and the radiation which would otherwise have killed us. Then, for whatever reason, we took it upon ourselves to move out of this earthly paradise, a transition which necessitated the donning of more than just a strategically positioned fig-leaf. Moving further north meant wearing clothes and following fashion. Think about it – no other animal on this planet has to build shelters, insulate and heat those shelters and still wear multiple layers of clothing just to stay alive, which shows how poorly suited we are to our current environment. It also explains why we have a primeval love of warm weather and stripping off whenever the opportunity presents itself.
Moving north towards Europe meant that we gradually lost more and more protective skin pigmentation, as having paler skins made it easier to absorb rays to make vitamin D. However, layers of clothing also means that the sun never reaches those parts once so blissfully exposed. Most of the world’s population today lives in the northern hemisphere, and the further you are from the equator, the less vitamin D you make. And from October to April you can expect to make none at all. The darker your skin, the worse off you are: black people only synthesise about one-sixth of the vitamin D that white people synthesise on exposure to sunlight.
Your only other hope – and it’s a very important one, whatever your skin pigmentation – is diet. This vitamin (which is actually really a hormone) is only available naturally in some animal-derived foods, especially oily fish (the food which keeps on giving), and eggs. Those hardy folk who live close to the Arctic would have died out long ago were it not for all the seal blubber and oily fish they consume.
Not only is vitamin D deficiency linked to rickets and other bone disorders, but also sudden infant death syndrome (SIDS), TB, heart disease, multiple sclerosis and a variety of cancers: breast, prostate, colon, pancreatic, ovarian and Hodgkin lymphoma. Therefore anything that blocks your ability to make vitamin D is potentially harmful.
Sunlight has two ultraviolet rays: UVA and UVB. UVB is the one needed to make vitamin D but can also cause your skin to burn. UVA is more damaging as it can penetrate the outer skin and reach the cells that can become cancerous.Sunscreen protects against burning, but when it comes to preventing skin cancer, that’s quite another matter. There are three main types of skin cancer associated with excessive sun exposure – cutaneous melanoma (the most lethal), basal cell carcinoma (the most common form) and squamous cell carcinoma. And the truth is, there is no evidence that they (sunscreens) protect against basal cell carcinoma or melanoma …. sunscreen companies have emotionally and inaccurately promoted the use of sunscreens. (not my words, before you sue. See Berwick below) They might not prevent cancer, but sunscreens block the formation of vitamin D. According to the World Health Organization, malignant melanoma from sun exposure is relatively rare, compared to the number of diseases caused by lack of exposure. That’s quite a statement, when you think about it. I’ve not even got on to the chemicals in sunscreen – I’ll save that for a sunny day.
Mead, M.N. (2008) Benefits of sunlight: A bright spot for human health. Environmental Health Perspectives, 116(4):A160-167.
Lucas, R., McMichael, T., Smith, W. and Armstrong, B. (2006) Solar ultraviolet radiation: global burden of disease due to ultraviolet radiation. Environmental Burden of Disease Series, No. 13. World Health Organization (2006)
Berwick, M. (2011) The good, the bad, and the ugly of sunscreens. Clinical Pharmacology & Therapeutics, 89(1):31-33.
I have the answer: Ride a bike or walk to and from work. For most of the year that will give you plenty of light and sun and you can skip the sunscreen early and late in the day.
As long as you remember to strip off first of course and let those rays in.
I bet the same companies which developed the sunscreens are very closely related to the ones which are busily promoting Vitmain D dietary supplements – when the best source is free natural sunlight.
I am sure Brtiish Naturism would know a thing or two about the benefits of sunshine…Once the initial guffaws and nudge nudge wink winks have been got out of the way a vist to their web-site might be in order.
All part of the bigger picture. The prudification of society is a serious and growing problem. More and more skin covering means less and less vitamin D.
I have for some time rejected the discredited ‘avoid the sun’ and ‘slap it on’ message, combined with our general cover up culture in favour of getting out in the sun regularly and stripping off as often as possible. The important point being to build up tan gradually and only stay in strong sun for limited periods when there is a risk of burning, rather than using sun-screen which may increase the risk of cancer by enabling people to stay too long in strong sun. This is the natural way to build up vitamin D, and appears more effective than supplements, which are best kept for those unable to build up sufficient vitamin D naturally. These days, the world seems to be made up of those who rarely go outside, those who stay covered at all times, and those who are covered most of the time but then binge on sunshine on their holidays and get horribly burned.
People need to learn that regular sunshine in limited doses is good for them – so many are now paranoid about skin cancer due to the ‘cover up in the sun’ and slap it on’ campaigns, which may be more appropriate in Australia than in northern Europe..
I was appalled that the BBC only seemed to think that the answer to vitamin D defficiency was generally to take supplements, which are not very effective, rather than to get out regularly in the sun and cover up less (while avoiding sunburn).
Yes Martin you are quite right – the best approach is to have frequent short bursts of sun exposure and avoid the binge/burn. It is sadly ironic that sunscreens offer little or no protection against cancer. I like the BBC but take their health bulletins with a pinch of salt – they read like press releases from pharmaceutical companies most of the time and rarely challenge the official position.
Which may be why we feel so down when we’ve had a bad summer – the only window of opportunity to get out there and get some rays – vitamin D – passes us by for another year. Another reason to eat lots and lots of oily fish.
Well Chris – it seems to me then that naturism is an expression of our intuitive, primeval need to expose ourselves to sunlight! And by the same token who doesn’t hate having to wear layers and layers of clothing just to maintain a normal body temperature? So slathering on the sunscreen when you do strip off is just counterintuitive.