An open letter signed by 138 global experts has been distributed to government's around the world, urging them to make vitamin D part of their coronavirus response strategy after much evidence has suggested the vitamin may reduce transmission, hospitalisation and even death rates.Previous research has already suggested that those who are hospitalized with COVID-19 may experience less severe complications if their levels of vitamin D is sufficiently high. However, despite the research, the UK’s National Institute for Health and Care Excellence (Nice) has recently concluded that ‘there is currently not enough evidence to support taking vitamin D solely to prevent or treat COVID-19’. The letter was sent to Boris Johnson and health Secretary Mike Hancock on Monday the 21st of December, advising that healthy adults should increase their daily vitamin D intake to 2,000 - 4000 international units (IU) during the pandemic.With winter creeping in and sunlight hours being reduced, the NHS usually advises for all people to take a Vitamin D supplement in order to get their daily dose of the ‘sun vitamin’. However, this standard recommendation is for just 400 IU, showing just how much more vitamin D is needed to combat the virus.Experts have revealed that the vitamin D is ‘exceptionally safe’ even when taken in such high doses with many claiming to take up to 4000 IU’s a day. The signatories of the letter revealed that ‘global patterns and risk factors for the COVID-19 pandemic and vitamin D deficiency match precisely’.One of the main organisers of the letter Dr Gareth Davies revealed the success other countries have had when it comes to incorporating vitamin D into their coronavirus response:Finland is the only country with an effective vitamin D food fortification programme and has had one of the best pandemic responses globally, with only 484 deaths and 22,500 recoveries [at the time of speaking].The independent researcher went on to outline that Japan’s levels of fish consumption have created a vitamin D rich diet for residents, which could have contributed to a lower coronavirus death rate, despite having twice the population density as Italy, who experienced 65,000 more deaths:Japan is an interesting case they eat so much raw fish, one of the few natural sources of vitamin D in food, that their diet is rich enough to be sufficient over winter. Japan had [around] 188,000 [coronavirus] cases, yet under 3,000 deaths. This is a population that is the same latitude as Italy, but twice as population dense.The letter also detailed that vitamin D deficiency can also lead to an increase in cases of repertory issues as well as inflammation, both of which are complications of coronavirus. Severe complications from the virus come about when the immune system overreacts to the infection. This also results in an inflammatory response that can cause damage to vital organs.So far, more than 70 studies have linked higher rates of vitamin D to lower rates of coronavirus infection as well as lower hospital admission rates and coronavirus death rates. Despite this, NICE has argued that was ‘not possible to determine a direct relationship between vitamin D and COVID-19 based on the available evidence’.However, NICE does still recommend residents continue to take vitamin D supplements in the winter as per recommendation by the NHS.The NHS recommends 400 IU per day of the vitamin for both children and adults, but signatories of the open letter have argued that Vitamin D is ‘exceptionally safe’ and that the daily recommended dose by the NHS just isn’t enough they even blamed the current recommendation on ‘a well known statistical error identified six years ago’.It seems that signatories are even urging people not to wait for government advice due to vitamin D’s already established safety levels, labelling the vitamin’s safety as more like that of face masks. The letter revealed:Vitamin D is much safer than steroids, such as dexamethasone, the most widely accepted treatment to have also demonstrated a large COVID-19 benefit. Vitamin D’s safety is more like that of face masks.The writers of the open letter continued to urge people all over the world not to wait for confirmation to take increased levels of the supplement:There is no need to wait for further clinical trials to increase use of something so safe, especially when remedying high rates of deficiency or insufficiency should already be a priority.Experts taking part in the letter are instructing ‘governments, doctors and healthcare workers worldwide to immediately recommend and implement efforts appropriate to their adult populations to increase vitamin D, at least until the end of the pandemic’.Experts recommend that adults to up their vitamin D intake to 2,000-4,000 IU depending on factors such as existing vitamin deficiencies and the possibility of vitamin deficiencies in those with darker skin tones and those who have been housebound.Those with existing or a higher potential for vitamin D deficiency should opt towards a vitamin D at the higher end of the scale. And, for those who have not been taking supplements for the vitamin should ‘get 10,000 IUs [250mcg] daily for two to three weeks, followed by the daily amount above’. The letter continued:The body can synthesise more than this from sunlight under the right conditions, e.g. a summer day at the beach. Also, the NAM [National Academy of Medicine in the US] and EFSA [European Food Safety Authority] both label this a ‘no observed adverse effect level’ even as a daily maintenance intake.Signatories have also requested that medical professionals assess hospitalised patients’ levels of vitamin D and treat those whose levels are insufficient. The letter continued to highlight that of all treatments and preventative measures, vitamin D is by far the least risky and least expensive:Many factors are known to predispose individuals to higher risk from exposure to [the coronavirus], such as age, being male, co-morbidities, but inadequate vitamin D is by far the most easily and quickly modifiable risk factor with abundant evidence to support a large effect.The letter concluded that ‘vitamin D is inexpensive and has negligible risk compared to the considerable risk of COVID-19. Please act immediately’.