37.3% of the UK population are deficient in Vitamin D which is a potential worry as Vitamin D helps absorb calcium from the gut and is therefore extremely important for bone health.
But Vitamin D is actually a potent steroid hormone and its influence goes way beyond bones and is particularly associated with immune, respiratory and mental health.
A recent review of 195 studies involving over 168,000 patients highlighted an association between depression and reduced brain function in the elderly and low levels of Vitamin D. 28 of the studies based in the UK showed that middle aged and elderly adults have a 33% greater chance of avoiding heart disease if their Vitamin D levels were sufficiently high. So how do we get our daily allowance of 600 IUs (international units) for those between 51 and 70 and 800 IUs for the over 70’s? The best way is directly from the sun as it is manufactured by the action of sunlight on our skin and why it is often referred to as the Sunshine Vitamin. But the sun needs to be 50 degrees above the horizon for the UV rays to be strong enough.
In Britain this only occurs in the summer months between May and September. If we expose 40% of our bodies to the sun daily during the summer months for 15 to 20 minutes or until the skin turns slightly pink then we can produce a plentiful 10,000 IUs. We should then cover up as the professional advice is “little and often”. If you are spend the majority of your life indoors then you need to maximise those summer months for bone and immune health. Between September and April we should consider taking a daily supplement along with good dietary sources of calcium which is contained naturally in all fruits and vegetables but particularly green, leafy vegetables. Food sources of Vitamin D provide only a little; wild salmon has the most at 1,000 IUs for a 3oz portion, one egg provides 26 IUs and a cup of mushrooms provides 12.6 IUs.
It is always advisable to seek your GPs advice when taking supplements or ask a qualified dietician or nutritional therapist.