According to official figures, more than 2.5 million people at risk in England are offered a free supply of vitamin D by the government.
In the plans announced on Saturday, nursing homes in England will automatically receive replenishment for their residents.
People on the list at extremely high clinical risk are given the opportunity to decide in a letter to supply their homes.
Free shipments begin in January and provide up to 2.7 million people with vitamin D worth four months.
Public Health England (PHE) advises everyone to take 10 micrograms of vitamin D a day between October and early March, especially the elderly, people who don’t go outside, and people with dark skin.
Vitamin D is often referred to as the sun vitamin as most people should be able to get all of the vitamin D they need from sunlight by around the end of March through the end of September.
The body makes vitamin D from direct sunlight on the skin outdoors, but people don’t get enough vitamin D from sunlight between October and early March.
In addition, many are at higher risk of vitamin D deficiency due to the Covid-19 pandemic and lockdown measures.
Health Secretary Matt Hancock said: “Because of the incredible sacrifices the British people have made to fight the virus, many of us have spent more time indoors this year and we may be vitamin D deficient.
“The government is taking steps to ensure that vulnerable people have access to free care to help them survive the darker winter months.
“This will support your overall health, keep your bones and muscles healthy, and significantly reduce the pressure on our NHS.”
Everyone who can buy vitamin D supplements is advised to take them immediately, even if they are eligible for delivery next year.
Research is currently exploring the link between vitamin D and Covid-19 protection, including a project at Queen Mary University looking at whether correcting people’s vitamin D deficiency over the winter increases the risk and / or the May reduce the severity of Covid-19 and other acute respiratory infections.
Mr Hancock has asked PHE and the National Institute for Excellence in Health and Care (Nice) to re-examine the existing evidence on the link between Vitamin D and Covid-19 to ensure we are exploring all potential ways to fight this virus.