Sunshine is the best source of vitamin D. Exposure to the sun is even more effective than diet in providing what our body needs. If you are self-isolating, try to spend some time outdoors in your garden or on your balcony. If that is not possible then, like in autumn and winter, you may not be getting enough sunshine right now. That’s why you might need to take a daily supplement containing 10 micrograms of vitamin D.
Many foods are naturally rich in vitamin D and so, as always, make sure to include them in your diet: cod liver oil contains a lot of vitamin D. If you don’t like the strong taste, then opt for oily fish such as salmon, sardines, pilchards, trout, herring, kippers and eel. They contain reasonable amounts of vitamin D, so try to eat them more often if possible.
Egg yolk, meat, offal and milk contain small amounts, but this varies according to season.
Margarine, some breakfast cereals and some yoghurts are fortified with vitamin D.
For more information see the British Dietetic Association website.