Vitamin D helps regulate the amount of calcium and phosphate in the body.
These nutrients are needed to keep bones, teeth and muscles healthy.
A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults.
Government advice is that everyone should consider taking a daily vitamin D supplement during the autumn and winter.
People at high risk of not getting enough vitamin D, all children aged 1 to 4, and all babies (unless they’re having more than 500ml of infant formula a day) should take a daily supplement throughout the year.
Osteoporosis: Vitamin D for bones (theros.org.uk)
Osteoporosis: Calcium (theros.org.uk)
There is also a calculator on each page which helps you work out how much you are getting from dietary sources.