At the Hay Literary Festival in May the geneticist Steve Jones spoke about the health benefits of taking vitamin D supplements. He said that, although in the past he thought that taking nutritional supplements was nonsense, he now takes vitamin D every day. That’s quite a turnaround but he’s probably right to do so.
Vitamin D – the Sunshine Vitamin
The best source of vitamin D is sunshine. Spending time with bare skin exposed to the sun without any sunscreen is needed for the manufacture of vitamin D in the body. On days when this is not possible, or during the winter months supplemental vitamin D3 is highly recommended.
Vitamin D and Rickets
As Jones pointed out, children today spend even less time outside than children did just 10 years ago. This is largely due to the allure of smart phones and tablets. In the 1950s doctors believed that the bone disease rickets had been more or less eliminated from Britain. Rickets is usually caused by a lack of vitamin D or calcium in the diet of children during bone development. Vitamin D aids the absorption of calcium into the bones. Sadly, rickets is back, despite being entirely preventable for most people. Its return is largely due to indoor lifestyles and the over use of sunscreens meaning bare skin is hardly ever exposed to the sun.
Of course, it is important to exercise caution when sunbathing. Getting sunburnt is not recommended as it may increase the risk of skin cancer. So get to know your skin and only stay out as long as you can before going pink.
Benefits Beyond Bones
As well as being vital for bone health vitamin D is also protective against obesity, kidney disease, heart disease, diabetes and multiple sclerosis. Vitamin D has particular benefits to the immune system, helping to tackle infectious diseases.
Don’t forget the K2
Vitamin K comes in various forms including K1, found in green vegetables, and K2 found in fermented foods such as natto, cheese and sauerkraut. Certain gut bacteria also produce vitamin K2, though this may not be bio-available to us. K2, together with D3, help prevent osteoporosis and atherosclerosis as they are both needed to drive calcium from the arteries to the bones. Calcium in the arteries means the arteries and blood vessels become narrowed leading to an increased risk of heart disease.
Supplementing with vitamins D3 and K2 is not known to have any negative side effects at standard doses, so is a risk free safety net against heart disease and osteoporosis.