Care homes will automatically receive deliveries of the supplements and clinically extremely vulnerable patients will be sent a letter asking if they want to opt in for free deliveries to their home.
In total around 2.7m people will receive the supplements. The supplies will be sent out in January and provide enough vitamin D to last for four months.
The government said there was a higher risk of vitamin D deficiency in these groups because they have spent less time outdoors this year as as result of the pandemic.
Vitamin D and COVID-19
Earlier this month health secretary Matt Hancock instructed NICE and Public Health England to look again at current evidence and make recommendations on the role vitamin D could play preventing and treating COVID-19.
NICE's initial rapid evidence summary, which was published in June this year, found there was 'no evidence to support taking vitamin D supplements to specifically prevent or treat COVID-19'.
However, a recent study found that 82.2% of people hospitalised with COVID-19 were deficient in vitamin D.
Mr Hancock said: 'Because of the incredible sacrifices made by the British people to control the virus, many of us have spent more time indoors this year and could be deficient in vitamin D.
'The government is taking action to ensure vulnerable individuals can access a free a supply to last them through the darker winter months. This will support their general health, keep their bones and muscles healthy and crucially reduce the pressure on our NHS.
'A number of studies indicate vitamin D might have a positive impact in protecting against COVID-19. I have asked NICE and PHE to re-review the existing evidence on the link between COVID-19 and vitamin D to ensure we explore every potential opportunity to beat this virus.'