You Are My Sunshine?

It may not have been incontrovertibly demonstrated that Vitamin D supplements offer protection from the effects of a Covid-19 infection but the evidence does seem to be stacking up (https://www.theguardian.com/lifeandstyle/2021/jan/10/does-vitamin-d-combat-covid). Vitamin D was formerly safely added to margarine and other spreads in the UK, as well as currently being a required supplement of milk products in Finland (it prevents Ricketts). This vitamin is manufactured in the deeper layers of the human skin by exposure to the UV radiation in sunlight. Pretty obviously, vitamin D will not produced to the same extent, when people:- a) Have darker skins, preventing penetration of UV light (some ethnic groups appear more susceptible to Covid-19 than others); b) In their winter season, live at latitudes near one of the poles where sunshine will be weaker and c) Rarely go outside as a result of self-isolation or instructions to 'stay at home' (this would be accentuated in this 2nd wave by 'b' and be particularily evident in prison and NHS populations). Quite a high proportion of the UK population are currently likely to be vitamin D deficient (especially at this time of the year and in a pandemic lockdown). The vitamin is cheap to give as a supplement. Vitamin D has no negative health consequences, unless it is taken in massive doses over an extended period of time. Given all the positive indications, I think it would be a good idea for the UK government to encourage (and perhaps even pay for?) vitamin D supplementation for many groups of people. It certainly wouldn't do any harm. If NICE thinks that the evidence for a positive effect of vitamin D on a patient's ability to deal with a Covid-19 infection is currently inadequate, studies should be fast-tracked. Simples!