For years we have been told to avoid the sun to reduce the chances of getting skin cancer. This is very important for places that have strong sun, like here in Australia. But have we gone overboard and inculcated a fear of the sun to such an extent that sun avoidance is leading to vitamin D deficiencies? Are these contributing to other diseases, including other cancers? Is the sun a natural remedy for health?
Skin cancers are a very real problem. They particularly hit people who have lived an outdoor lifestyle either for work or for leisure. It seems reasonable and realistic to get people to reduce their risk by "slip, slop, slap", slipping into a hat and lightweight clothes that cover arms and legs and slop on lots of sunscreen lotion to stop the damage from the sun's rays. However it now looks as though we might have gone to far and we are now losing to many benefits that the sun brings, particularly vitamin D.
For years vitamin D was understood to be needed for bone health and strength and dietary recommendations were developed with the assistance of the orthopedic (bone) specialists. In the last few decades it has been discovered that vitamin D is needed in all cells, not just bone cells, and useful in the prevention of some cancers, and a range of other diseases
Back in 1985 the Lancet, one of the top prestigious medical journals published an article which showed that cancer of the colon was much more common in areas where there was the least sun. A 19 year study showed that that those with the highest vitamin D levels had the lowest rates of colon cancer - only one third of the risk. If we look at the numbers who die in Australia from colon cancer (4700) and do the math from the figures in this article we would find some very interesting results. If everyone had their vitamin D levels at the same levels as those in the highest vitamin D group then about 1600 lives would be save a year, which is the same number as die from skin cancer Australia.
This is just one cancer. There are indications we need more vitamin D not just to prevent colon cancers but other cancers and diseases as well such as: cardiovascular disease, hypertension, type 2 diabetes, prevention of type 1 diabetes, osteoarthritis, multiple sclerosis, depression, epilepsy, migraine headaches, polycystic ovary syndrome, musculo-skeletal pain, various autoimmune conditions like Graves disease, ankylosing spondylitis, SLE, rheumatoid arthritis and various cancers including breast, ovary, prostate, bladder, esophagus, kidney, lung, pancreas, rectum, stomach, uterus and non-Hodgkins lymphoma.
That is a huge list of conditions. So what does this mean in practice? So how do we best get Vitamin D? If you want to go and get nature's natural remedy for health you'll spend a little more time in the sun and if you live in cloudy countries you may need to be vigilant in making the most of the sun in your climate. The Vitamin D Council in the US recommends regular mid-day sun exposure in the US. In Australia they get very upset by the mid-day idea. But be sensible - just don't get burned.
Vitamin D can also be taken as a supplement. If you want to know if you need it then have a blood test to find out your current levels and then you will know the dosage you will need to bring you up to the necessary levels. The Vitamin D Council recommends your blood levels should be 50-80ng/ml which in the other measurement system is 125-200 nmol/L.
If you are just a little under then 1000 IU per day supplement should be fine. If you are well under you might need 5000IU or 10,000 IU per day to make sufficient difference especially if you spend most of your time inside or the weather is very cloudy.
Just a note - there are some people who spend a lot of time outside but still have low Vitamin D levels, particularly dark skinned and well-tanned people, so don't just assume that you are OK. Some tanned leathery elderly surfers who spend all day in the sun are Vitamin D deficient and if they can be then so can you.
In theory 30 minutes of summer sun should give you 10,000 IU but many don't have optimally functioning bodies and the conversion of sun to the vitamin is blocked out somehow. One suggestion was that older bodies don't have enough necessary cholesterol just below the skin to make the vitamin D properly. That might just be part of a much bigger issue - that of optimal health and bodily functioning. But one thing is for sure, your body will function much better if you have sufficient vitamin D.
Lappe, JM et al. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. American Journal of Clinical Nutrition 2007;85:1586-1591 Garland, C et al. Dietary vitamin D and calcium and risk of colorectal cancer. The Lancet 1985;325 (8424): 307-309 For a review of medical papers and useful references try: Vasquez, A, et al. The clinical importance of vitamin D (cholecalciferol): a paradigm shift with implications for all healthcare providers. Alternative Therapies, 2004; 10(5): 28-37
