Following Southampton's sneak preview of summer, here's all you need to know about Vitamin D (for when it returns!)

Last week's impromptu mini-heatwave led to a fair few discussions with my personal training clients about vitamin D, why we need it and how we can be deficient without even knowing it. 

Of course getting enough sunlight; something we will hopefully be blessed with much more of over the next few weeks; is part of it but as there is so much more information regarding vitamin D’s importance, I thought I’d best let you know the parts that I wish I’d been aware of years ago.

Southampton personal trainer Gen Preece Boot camp

What actually is it?

Without being too sciency, vitamin D is actually a hormone that we naturally produce in the skin when UVB light hits it. It then converts cholesterol to pre-vitamin D, and then to vitamin D3 (cholecalciferol) in the liver.

It enables the absorption of Calcium and Phosphorus from the intestines and regulates gene expression in over 2000 of our 30,000 genes.

Why is it important?

Vitamin D helps us to:

  • absorb calcium and phosphorus, to maintain healthy bones and teeth.
  • support normal cell division.
  • keep the immune system functioning normally, including the body’s inflammatory response to infection and wounds
  • maintain normal muscle activity

What affects our body’s vitamin D production?

Numerous factors such as location (latitude and altitude), time of year (we certainly require more vitamin d in the winter months) time of day, cloud cover and levels of air pollution.

The greater a person’s body fat levels, the less vitamin D available for tissues and organs. This is because it is being stored in those fat cells!

Age is also a big factor, as we produce less vitamin D as we get older. Many elderly people also spend far less time in the sun than they used to (aside from the sun-worshippers that I train!) which also plays a large role in the rising rates of osteoporosis.

Southampton personal trainer Gen Preece Boot camp

Whereas I wouldn’t recommend stepping out in the hot midday sun without appropriate sun factor protection, it’s important to remember that sun cream does block the skin’s vitamin D production. The darker a person’s skin, the higher the melanin content – meaning the more sunlight they actually require in order for the body to manufacture vitamin D!

If you’re concerned you might be vitamin D deficient, please check with your healthcare practitioner, who will be able to advise the correct dosage of vitamin D3/K2 that you require.

See you in the sun! Gen x

Southampton personal trainer Gen Preece Boot Camp