The Importance of Vitamin D

I often hear people saying they’re topping up their Vitamin D by spending time outdoors in the sunshine – it’s an odd thing to ask, but is it really that simple to do?

Firstly, why do we need Vitamin D?

  • strong bones – it helps to prevent against osteomalacia (softening of the bones)
  • helping the body absorb calcium – which helps to maintain normal muscle functioning
  • it regulates the quantities of calcium and phosphate in your body (important for healthy teeth and bones)

A WebMD article titled “The Truth about Vitamin D” gives us further information on the need for Vitamin D:  “Vitamin D deficiency has now been linked to breast cancer, colon cancer,prostate cancer, heart disease, depression, weight gain, and other maladies. These studies show that people with higher levels of vitamin D have a lower risk of disease, although they do not definitively prove that lack of vitamin D causes disease — or that vitamin D supplements would lower risk.”

“The Vitamin D Council — a scientist-led group promoting vitamin D deficiency awareness — suggests vitamin D treatment might be found helpful in treating or preventing autism, autoimmune disease, cancer,chronic pain, depression, diabetes, heart disease, high bloodpressure, flu, neuromuscular diseases, and osteoporosis. However, there have been no definitive clinical trials.”

What are the best sources of Vitamin D?

Sunshine – from ultraviolet B (UVB):

The key thing here is that you need to expose bare skin to the suns rays – UVB won’t penetrate through clothing. More skin exposed increases the Vitamin D that is produced. There are a few things to consider. Firstly, darker skin needs to be exposed longer than fair skin; but no sunburn please – you can get enough Vitamin D without sunbathing for hours on end or even turning pink. Secondly, the closer to the equator you are, the easier it is to produce Vitamin D all year round – that’s because there is less atmosphere for the UVB rays to penetrate through. Thirdly, the time of day you are exposed to the suns rays – more Vitamin D is produced from exposure around midday.

What is surprising to learn, is that if you are in the UK, during the months from around October to April, the angle that the earth rotates are means UVB rays don’t reach us in the quantity needed to get enough Vitamin D.  Effectively we could have 6-7 months when we are simply not able to ‘top up’ our Vitamin D from the sun’s rays.

Other things that affect the quantity of Vitamin D your body will produce when exposed to the suns rays:

  • sunscreen – clearly designed to block UVB rays
  • altitude – there is increased intensity at higher elevations
  • your age – the younger you are, the easier it is for your body to produce Vitamin D
  • air pollution – a bit like the effect the atmosphere has, because the UVB can be prevented from reaching us
  • being inside – most glass stops UVB, so even if you are enjoying the sunshine, the glass prevents UVB exposure

So what can we do if, like us, you live in the UK…

Boost your Vitamin D intake with good nutritional choices:

  • red meats
  • fish – the oily ones like wild salmon, mackerel and sardines
  • liver
  • egg yolks
  • mushrooms (that have been exposed to ultraviolet light)
  • fortified dairy foods
  • some breakfast cereals – check the labels

Take supplements:

Taking a supplement (tablet or liquid form) is a good way to boost your Vitamin D intake.

If you would like to know more about how much Vitamin D you need and whether you can get too much follow this link to the WebMD article, “The Truth about Vitamin D“.

The Scientific Advisory Committee on Nutrition (SACN) reviewed (July 2016) the evidence on vitamin D and health to see whether dietary recommendations in the UK (set in 1991) were still appropriate.

For adults, the SACN is now recommending:

  • “a reference nutrient intake (RNI) of 10 micrograms of vitamin D per day, throughout the year, for everyone in the general population aged 4 years and older
  • an RNI of 10 micrograms of vitamin D per day for pregnant and lactating women and population groups at increased risk of vitamin D deficiency

The RNI and safe intakes were developed to ensure that the majority of the UK population has enough vitamin D to protect musculoskeletal health, all year round.” The full SACN report on Vitamin D and Health can be found on their website.

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