Recent articles in the press discuss the potential of Vitamin D supplementation to reduce the risks of Covid-19.

This article will provide key research information on the benefits of Vitamin D for the immune system plus pharmacist advice on which indication has sufficient clinical research to support its use.

What is Vitamin D?

Vitamin D is called the sunshine vitamin because it is produced naturally by the action of sunlight on the skin.

NHS England recommends a daily supplementation of 10 mcg (micrograms) from oily fish such as salmon and sardines or vegetarian/vegan friendly sources. The latter are either synthetic (man-made  vitamin D3) or from mushrooms (vitamin D2). One natural vitamin D3 version exists which is derived from marine algae. Vitamin D3 is better absorbed by the body compared to vitamin D2.


Why is Vitamin D important?

    A study, published in the BMJ in 2017 which reviewed data from 25 trials, showed the vitamin can help prevent acute respiratory infections, particularly in those patients with a pre-existing vitamin D deficiency.

    Professor Martineau, who was the lead author of the review, stated ‘When vitamin D is made in the skin, it gets converted in the liver to a form that circulates around the body. This creates a natural antibiotic-like substance in the lining of the airway that can bash viruses and bacteria, killing them’.

    ‘It is a generic effect: we don’t know yet whether that would work against Covid-19.’

    Research from the University of Birmingham carried out in 2018 demonstrated that vitamin D deficiency trebles the length of hospital stay.


    Can Vitamin D be used to treat Covid-19?

      Previous studies and data reviews have shown that Vitamin D can help prevent and treat respiratory infections such as community acquired pneumonia.

      However, despite the recently quoted Irish study suggesting that high dose vitamin D could be used as part of the Covid-19 treatment program there is still insufficient evidence for its role in reducing the risk of the coronavirus.


      Who is susceptible to Vitamin D deficiency?

        It is thought that around 1 in 5 adults and children in the UK are deficient in Vitamin D. The recent coronavirus lockdown, on top of (sensible) use of sunscreens may have contributed to decreased levels of vitamin D in the blood.

        Research has shown that levels of deficiency are higher than expected in the general population. Research from The University of Surrey discovered a high number of students had very low levels vitamin D at the end of the summer term when levels were expected to peak.


        What can I do to increase my levels?

          Daily exercise outdoors will help boost levels.

          10 minutes exposure for pale skin on the arms and face, darker skin may need around 25 minutes exposure to stimulate Vitamin D production.

          Ethnic groups with dark skin need more daily sunlight exposure and should also take a year-round supplement.


          Which are the effective Vitamin D supplements?

            Vitamin D supplements are widely available.

            The most easily absorbed version is called D3 but these supplements are commonly made from synthetic or animal sources.

            One vegan friendly, marine algae sourced D3 is available and this is used in The Naked Pharmacy Saffrosun supplements. There are also mushroom derived D2 alternatives.

            The recommended dose is 10mcg (or 400iu) daily and should be taken for several months to build up healthy vitamin D levels.