A group of independent scientists (the Scientific Advisory Committee on Nutrition) have taken a comprehensive look at the link between vitamin D and health. Public Health England’s head of nutrition science, Dr Louis Levy, answers questions about the report and explains what it means for you and your family.

What are the vitamin D recommendations?

The evidence shows us that to keep our bones and muscles healthy we need vitamin D equivalent to an average daily intake of 10 micrograms.

To ensure this is happening we all need to look at our lifestyles and diets and consider whether we need to take a vitamin D supplement.

For instance, vitamin D is made in the skin by the action of sunlight, and some foods contain vitamin D, so if you know you eat a healthy balanced diet and get some sun then it’s likely you’ll be getting enough vitamin D during the spring and summer.

During the autumn and winter our only source of vitamin D is our diet and it’s actually quite difficult to meet the recommended levels from food alone so it’s worth everyone considering a daily supplement containing 10 micrograms of vitamin D.

However, if you get little or no exposure to the sun – for instance you live in a care home or perhaps cover your skin when outside – you should take a daily supplement containing 10 micrograms of vitamin D.

People with dark skin, from African, Afro-Caribbean and South Asian backgrounds, may not get enough vitamin D from sunlight in the summer and should also consider taking a 10 micrograms supplement all year round.

Finally, children from birth to age 4 should also take a supplement - visit NHS Choices for full details.

Why is this recommendation being made now?

The previous recommendations on vitamin D were made in 1991 but over the years we’ve seen more research emerging about vitamin D and health and at the same time we’ve also learned more about skin cancer, the damage that the sun can do our skin and the need to limit our time in the sun. The developing evidence meant that now was an appropriate time to look at this issue again.

Why don’t you believe food can provide all the vitamin D we need?

Vitamin D is only found in a small number of foods so it’s not easy to get what you need from your diet alone. Certainly a healthy balanced diet based on the Eatwell Guide helps; foods containing vitamin D include oily fish, red meat, liver or egg yolk whilst some breakfast cereals and fat spreads are fortified with vitamin D.

What if I spend plenty of time outdoors?

From spring to autumn sunlight is the main source of vitamin D for many people but we can’t say exactly how much sun is required to get what your body needs, particularly when balanced against the risks of damaging our skin if we spend too long in the sun. Between October and early March we don’t get any vitamin D from the action of sunlight on the skin which is why we suggest everyone considers taking a supplement in autumn and winter.

If I feel fine and have no health problems, why should I take a vitamin D supplement?

If you follow a healthy, balanced diet and get some spring and summer sunshine then you should be getting the vitamin D you need for a good part of the year. However we know that many of us don’t follow a healthy balanced diet and we can’t say exactly how much vitamin D we get from the sun, so a supplement is something for you to consider especially in the winter months.

A key role for Public Health England is to keep you informed when new evidence about diet and nutrition emerges and having looked at the best current evidence, we believe everyone should think about how much vitamin D they are getting to maintain healthy muscles and bones.

Why is 10 micrograms the necessary amount of vitamin D?

Recommendations are based on scientific evidence. Independent scientists examined high quality evidence from randomised controlled trials and cohort studies – the most reliable studies available.

Is it easy to buy vitamin D?

Most pharmacies and supermarkets sell supplements cheaply – look out for a daily supplement containing 10 micrograms (or 10 µg) or 400 International Units (400 IU). You may be able to get it free on prescription if you are eligible - speak to your GP. Women and children who qualify for the Healthy Start scheme can get free supplements containing the recommended amount of vitamin D.

This post originally appeared on the Public Health Matters blog, and has been republished with the permission of Public Health England.