Vitamin D, unlike most other essential nutrients, is not naturally found in many foods. It is mainly manufactured in our skin in response to sunlight. The life we lead now is very different to our ancestors who spent most of their time outside. Today’s world means that most people work indoors, children play inside and if they do go out wear high factor sunscreens in the summer.
Throughout the year in the UK we are usually well covered by clothing except on the warmest summer days. As a result vitamin D deficiency is becoming all too common.
Symptoms of Vitamin D Deficiency
Typical symptoms include:
- Bone pain and muscle weakness
- Tiredness and fatigue
- Cognitive impairment in adults
- Asthma in children
Most recently research found that vitamin D supplementation alongside asthma medication was shown to significantly reduce the risk of severe asthma attacks.
How much sunlight do we need to produce enough vitamin D?
Well, it’s complicated. There are many factors which influence the amount of vitamin D produced by each person. It is not quite as simple as saying spend 15mins out in the sun with hands and face exposed. The amount of sun we get in the UK between September and April is probably not enough to maintain our vitamin D levels through the winter. The type of skin you have will influence vitamin D production. Pale skin with less melanin produces vitamin D more quickly. Your age will influence your vitamin D levels, the older you are the more difficult it is for the skin to manufacture vitamin D. Your genes will also determine how efficiently you manufacture vitamin D.
Spending long periods of time outside with more skin exposed gives more chance of producing enough vitamin D but even then on a cloudy day or with the sun low in the sky as in the winter months we will struggle.
Public Health England have now recommended that everyone should take a vitamin D supplement of 400 IU each day, however, this is the recommended level to prevent deficiency but to achieve optimum health certain individuals may need higher doses.
A good place to start is to have a vitamin D test to see your current level. This can be done through your GP or privately with a simple, low cost, finger prick blood test. Supplements with vitamin D3 are best as they are more effective at maintaining blood levels of vitamin D.