Vitamin D helps to control the amount of calcium and phosphate in our bodies. Both are needed for healthy bones, teeth and muscles. Vitamin D is found naturally in a small number of foods, including oily fish, red meat, liver and egg yolks. It's also found in fortified foods like breakfast cereals and fat spreads. However, it's difficult for us to get the recommended amount of vitamin D from food alone.
Experts recommend everyone consider vitamin D supplements over winter. Headlines were prompted by new advice on vitamin D from Public Health England (PHE), which says that children and adults over the age of one should have 10 micrograms (mcg) of vitamin D every day. This means that some people may want to consider taking a supplement.
Our main source of vitamin D is from the action of sunlight on our skin, although roughly one in five people has low vitamin D levels, this is not the same as a vitamin D deficiency. It is not accurate to say that millions of people are at risk of deficiency.