Nutrition from the sun: Vitamin D
Today was truly the first taste of summer here in England. Temperatures rose to 22 degrees and I, and everyone else I could see, just lapped it up. Winter really is a gift, because without it, we don't appreciate the warmth as much. The flowers are so pretty at the moment and the whole world feels like it is waking up.
We really do need the sun for good health. And like the lady who ended up almost killing herself by eating too much bok choy somewhere in New York; too much of a good thing can be very unhealthy - but too little of the sun is often the problem in industrialised cities, especially those of northern latitudes. These are often places where, in fear of skin cancer and wrinkles, people are slapping on the sunscreen before they even head out - and it is not a good thing the majority of the time.
Vitamin D is actually a fat soluble hormone which our skin makes when it is exposed to UVB rays from the sun. A hugely important nutrient, vitamin D has many vital roles in human health:
- It helps to strengthen our immune systems - always getting sick? Check your vitamin D levels (simple blood test at the GP)
- Vitamin D assists in the absorption of calcium and promotes bone mineralisation. It also helps to maintain normal blood levels of calcium and phosphorus. You can take as many calcium supplements as you like, but if your vitamin D levels are off (along with many other bone nutrients), you simply can't absorb it properly.
- Research is increasingly showing that adequate vitamin D helps to prevent against super common conditions such as high blood pressure, psoriasis and several debilitating autoimmune conditions like multiple sclerosis and rheumatoid arthritis.
- There is growing evidence linking low vitamin D levels to the development of cancer (approximately 18 different cancers have been linked so far).
Countries in northern latitudes are at increased risk of deficiency because the UVB rays we need to synthesise vitamin D are only truly abundant in the summer months (approx. May to Sept), so supplementing is a good idea. 2000IU/day of vitamin D3 is a good idea for most people (though those with autoimmune conditions will usually require much more - check with your consultant or dietitian).
Vitamin D is available in the diet but watch out for foods fortified with vitamin D - food companies will usually use the cheaper D2 which is not readily utilised by the human body. Vitamin D3 is what we're looking for and there is some available in eggs, salmon, tuna, mackerel and sardines.
Try to get out in the sun, without sunscreen, between 11am-3pm for approximately half the time it would take for your skin to go pink at least three times a week. Once you've done that you can pop on a shirt/sunscreen/hat....you will feel the difference. Happy spring everyone :-)