Vitamin D is a fat-soluble vitamin. It is also known as the 'sunshine vitamin' because we produce most of what we need through exposure to the sun. Although vitamin D also comes from food, it is difficult to get all your body's requirements from food alone. Sources of vitamin D include oily fish, mushrooms, egg yolks and foods which have been fortified with vitamin D.

Vitamin D controls absorption of calcium and phosphate by the body and is vital for keeping your bones and teeth healthy. That's why it is particularly important for pregnant women, breast-fed babies and children under 5 to produce enough vitamin D. Vitamin D also plays an important role in immune function, mental health and muscle function.

Symptoms of vitamin D deficiency can be vague, so not everyone will attribute their symptoms to low vitamin D. Symptoms include feeling low in energy, having more aches and pains than usual, depression, especially in winter, and constantly getting sick. Even if you don't have symptoms, it is worth testing your vitamin D as a high proportion of adults are deficient or have insufficient levels. If you're over 65, have dark skin or suffer from inflammatory bowel disease or other fat malabsorption conditions you may be even more prone to vitamin D deficiency.

Our doctors will tell you if your results are within the normal range and, if they aren't, what steps you can take to improve them.

Vitamins