Vitamin D is naturally produced in the skin in response to sunlight. As we age our skin is less able to convert sunlight to Vitamin D.
It is also found in a few foods such as oily fish , eggs, cheese, mushrooms, liver and some fortified cereals.
Up to 33% of people are deficient in Vitamin D due to a mixture of an indoor lifestyle, modern diets and English weather. This will only increase as the next generation lead more sedentary lifestyles.
Recent research has linked a lack of Vitamin D to a wide range of diseases such as a variety of cancers, Multiple Sclerosis, Diabetes, infections and Alzeimer’s.
There are some reports that suggest the people with a lack of Vitamin D age faster.
Middle aged people with high levels of Vitamin D in the blood are 20% less likely to get cancer and Vitamin D is also needed to help strengthen the bones.
A recent study conducted over 17 years in Japan showed that higher levels of Vitamin D in the blood were 20% less likely to develop any cancer. It was found to be especially effective in warding off liver cancer.
The researchers believe that the vitamin produces an enzyme, which “ detoxifies” natural acids in the body which in turn prevents damage to internal organs.
How much should I have?
You can get yourself tested and how much you have in your body will depend on how much you absorb from your food, and how much you absorb through your skin.
It is suggested by most experts that in winter and spring you should take around 600-800 IU per day.
You should take this year round if you are unable to get outside.
When outside try to expose as much flesh as you can to the sun for around 15-20 minutes with no sunscreen every 2-3 days.
British scientists have long called for Vitamin D to be added to common foods such as milk and bread- a policy which is already in place in USA, Canada and Australia
Vitamin D and Covid 19
There is a lot of scientific interest in the role vitamin D may play in your risk from coronavirus and this will continue to be an important topic. Some of this research is already under way.
Extract from The Lancet
Interest in a potential role for vitamin D in the prevention or treatment of acute respiratory infections dates back to the 1930s, when cod liver oil was investigated as a means to reduce industrial absenteeism due to the common cold. Meta-analyses of randomised controlled trials conducted from 2007–20 reveal protective effects of vitamin D against acute respiratory infections, albeit these effects were of modest size and with substantial heterogeneity.
The striking overlap between risk factors for severe COVID-19 and vitamin D deficiency, including obesity, older age, and Black or Asian ethnic origin, has led some researchers to hypothesise that vitamin D supplementation could hold promise as a preventive or therapeutic agent for COVID-19.
From a mechanistic angle, there are good reasons to postulate that vitamin D favourably modulates host responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), both in the early viraemic and later hyperinflammatory phases of COVID-19. Vitamin D metabolites have long been known to support innate antiviral effector mechanisms, including induction of antimicrobial peptides and autophagy
Pending results of such trials, it would seem uncontroversial to enthusiastically promote efforts to achieve reference nutrient intakes of vitamin D, which range from 400 IU/day in the UK to 600–800 IU/day in the USA. These are predicated on benefits of vitamin D for bone and muscle health, but there is a chance that their implementation might also reduce the impact of COVID-19 in populations where vitamin D deficiency is prevalent; there is nothing to lose from their implementation, and potentially much to gain.
Regardless of what this study tells us, if you’re not going out much, then taking a supplement would be a good idea because of the overall health risks of vitamin D deficiency.
There is already public health guidance, which has been in place since 2016, that everyone aged four and above should consider taking a vitamin D supplement especially in autumn and winter.
Many people have been spending more time than usual indoors and so may be at risk of vitamin D deficiency. People who don’t go out much or who cover their skin when outdoors, are particularly recommended to take a supplement all year round. In Scotland, people from ethnic minority backgrounds with darker skin are now recommended to take a supplement.
Sources- The Lancet
BHF