French doctors advise vitamin D to counter Covid this winter

Studies show links between vitamin D deficiency and serious forms of Covid-19. Doctors say winter supplements could help.

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Health body the Académie Nationale de Médicine in France has advised that people take vitamin D supplements in order to reinforce their “innate immunity” against Covid-19 this winter.

Studies have shown that vitamin D is effective in combatting illnesses that can affect the respiratory system, such as colds and flu. Ongoing studies are also investigating links between serious forms of Covid-19 and vitamin D deficiency.

In France, 41% of people have winter vitamin D deficiency.

Studies investigate link between vitamin D and Covid

A study published in the Journal of clinical endocrinology and metabolism on October 27 found that 80% of 230 hospitalised Covid patients in Spain had a vitamin D deficiency, compared with 47% in the general population.

Authors of the study pointed out that their results showed vitamin D deficiency to be a common point between patients, rather than the cause for their illness.

Another study beginning soon in the UK will provide 5,000 people with vitamin D treatments over 6 months to analyse how it affects their resistance to the virus in the winter months.

Vitamin D not a Covid “cure”

It is known that mortality in Covid-19 patients is linked to “cytokine storms” induced by the virus.

Earlier studies, such as this one published in Frontiers in Immunology in June, show that some Covid patients experience an over-reaction in their immune system, causing excessive production of proinflammatory cytokines. These aggravate acute respiratory distress syndrome and tissue damage causing multi-organ failure and death.

The Académie Nationale de Médicine says increasing vitamin D uptake will not constitute “a preventative treatment or a cure” for extreme forms of Covid-19 such as these.

However, it could provide effective “secondary” support and boost “innate immunity” among the wider population.

The World Health Organisation has recommended that people up their vitamin D intake over winter since 2017, with children seeing particular benefits from the vitamin.

What are the sources of vitamin D?

Our skin produces vitamin D naturally when it comes into contact with sunlight. This means that in summer months, many people have a naturally high vitamin D intake.

In winter, there is generally not enough sunlight to support this method of vitamin D production in sufficient quantities, especially in cloudy areas.

We can access some vitamin D-rich food such as fish, cod liver oil, veal liver, cheese milk and some soy milk.

However, this is still unlikely to provide sufficient intake. As such, taking vitamin D supplements is now recommended.

The Académie Nationale de Médicine has specified that vitamin D supplements are inexpensive and can be reimbursed by the Assurance Maladie.

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