The human body has the amazing ability to be able to produce vitamin D when skin is exposed to sunlight. It is suggested 90% of Vitamin D is derived in this way. Other sources include egg yolks, oily fish and whole milk and of course supplements. Some doctors consider it as the most important vitamin for our health and wellbeing.

So why do we need supplements? 

With the limited UK sun and many more people spending time indoors, our bodies don’t get the opportunity to produce Vitamin D the natural way. Supplements are a must for most people to make sure Vitamin D levels are topped up! 

One study estimates that around 20% of the population in the UK has a profound vitamin D deficiency

How does Vitamin D help?

  • Bones and Teeth - Vitamin D helps maintain and grow your bones and teeth. Vitamin D helps the body absorb calcium which boosts bone mineral density. 
  • Muscles - Vitamin D contributes to muscle function. In some studies, Vitamin D supplementation has been shown to increase muscle strength, particularly in people who are vitamin D deficient. Higher levels of Vitamin D in the blood are associated with reduced injury rates and improved sports performance.
  • Immunity - Many studies have reported an association of lower Vitamin D levels and increased rates of infection. 

Adrian Martineau, professor of respiratory infection and immunity at The London School of Medicine and Dentistry, Queen Mary University of London, has found that Vitamin D plays a role in improving respiratory infections.

When his team analysed data from clinical trials involving 11,000 patients, they found that taking daily or weekly vitamin D supplements can help reduce the risk of respiratory infections, asthma attacks and bronchitis.

Why Vitamin D3 and not D2?

Vitamin D3 is regarded as being more effective than D2 (Ergocalciferol). Both D2 and D3 have to pass through your liver and kidneys to be converted to the active form of vitamin. It is believed the human body is able to convert Vitamin D3 faster than D2.

How much Vitamin D should I take?

There is a wide range of expert opinions when it comes to how much Vitamin D we should supplement. According to the Department of Health recommendations, anyone above the age of four should have 10 micrograms (400 IU) daily particularly between October and March. People at higher risk (those with little or no exposure to the sun and people with dark skin) are advised to take a supplement all year round. The Department of Health also states 100 micrograms (4000 IU) as the recommended daily limit.

Is there such a thing as too much Vitamin D?

The main consequence of Vitamin D toxicity is an excess build-up of calcium in your blood. This can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity could progress to bone pain and kidney problems. It is important to stay within the recommended NHS limit. You can ask your doctor to check if you have the correct level of Vitamin D in your body.


All content within this column is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional.