Vitamin D

By Dietitian, Juliette Kellow BSc RD

How much you need each day:

• There’s no RNI for young adults.
• Women and men over the age of 65 years need 10mcg

Why you need it:

Vitamin D, in conjunction with calcium and phosphorus, is needed to form strong bones and teeth. In particular, it helps to absorb calcium from the intestine and so can help to prevent brittle bone disease or osteoporosis in later life.

Good food sources:

The main source of vitamin D for most people is sunlight – and as a result, it’s often called the sunshine vitamin. Ultra-violet rays from the sun act on a substance contained within the layer of fat beneath the skin to produce vitamin D. Dietary sources of vitamin D are limited to just a few foods, including oily fish like mackerel and sardines, eggs, liver, fortified breakfast cereals and margarine, which is fortified by law.

Too little:

A deficiency of vitamin D in babies and toddlers leads to soft bones and the development of rickets, characterised by deformed, bow-shaped legs. In adults, a prolonged deficiency of vitamin D leads to a disease called osteomalacia. Poor intakes of vitamin D also hinder the absorption of calcium, increasing the risk of osteoporosis is later life.

Top tip:

Even though it’s important to expose your skin to sunlight so that your body can make vitamin D, you don’t need to spend hours sunbathing! Just two hours of sunshine each week in the summer will maintain adequate levels throughout the rest of the year as this vitamin is stored in the body. Remember to follow all the usual sun safety advice and cover up during the hottest part of the day between 11-3pm, wear a sun screen and never let yourself burn.

How to get enough:

Food	Vitamin D Content (mcg)
160g smoked mackerel	12.8
100g canned sardines in tomato sauce	7.5
1 boiled egg	1.1
30g fruit ‘n’ fibre	0.6
100g grilled lamb’s liver	0.5
1tsp low-fat spread	0.4

Watch out!

Most people usually obtain enough vitamin D from the sun, but if you don’t expose your skin to the sunlight very often, a good dietary supply of vitamin D is essential. Elderly people and those who are housebound or keep their bodies covered whenever outside, are at greatest risk of deficiency.