• Vitamin D essential for bone and muscle health
  • Meeting the reference intake of 10 mcg per day can help to prevent osteoporosis and other health issues
  • Latest official guidance advises all adults to consider taking a vitamin D supplement
  • Those with a higher risk of deficiency may be able to get supplements for free through local health services
  • Vitamin D supplement Fultium D3 also available through Treated.com’s online pharmacy service

Last month, the National Institute of Health and Care Excellence (NICE) updated their guidance on the use of vitamin D supplements.

They recommended that access to vitamin D supplements should be increased, and also that Public Health England should lead on the development of national campaigns to raise awareness of the importance of vitamin D.

This comes following last year’s review by the Scientific Advisory Committee on Nutrition (SACN) into the subject in July 2016; in which they recommended an RNI (Reference Nutrient Intake) for those aged 4 and above of 10 mcg, or 400 IU, per day, throughout the year.

Prior to this, there were no specific reference intakes for vitamin D in the UK which related to the general population as a whole. DRVs (Dietary Reference Values) were initially set by the Committee on Medical Aspects of Food Policy (COMA) in 1991, and reviewed in 1998.

These only specified a reference intake (at the time 7-10 mcg, or 280-400 IU per day) for those at heightened risk of deficiency (such as children under the age of 3, women who were pregnant or breastfeeding, persons over 65s, people with limited exposure to sunlight, and women or children of Asian ethnicity).

It was held that, for the majority of people aged 4 to 64, vitamin D stores acquired through natural exposure to sunlight during lighter months in summer would be sufficient to offset the shortfall during darker months in winter.

These recommendations were made considering the benefits of vitamin D on bone health. However, various research since has found that vitamin D has various other health benefits too.

The SACN in 2010 announced that they would review the reference intake guidelines for vitamin D; which led to the above recommendations being made.

Where does vitamin D come from?

Our bodies produce vitamin D when our skin is exposed to sunlight; specifically UVB rays.

Vitamin D is also naturally contained in certain foods: namely oily fish (salmon and tuna), liver, red meat and eggs.

Other foods, such as breakfast cereals, may be fortified with vitamin D.

From the middle of spring (around the end of March) to the middle of autumn (the end of September) the vitamin D we get from sunlight is typically enough to keep our stores sufficient.

However, people in the UK don’t tend to get enough vitamin D through sunlight alone during winter months, because winter sun rays do not contain a level of UVB sufficient enough for our bodies to produce it.

During winter months then, our main sources of vitamin D are those either contained in our diet, or in supplements.

Why is vitamin D important?

Vitamin D assists in the metabolism of certain minerals in the body (phosphorus and calcium), which in turn maintain strong bones and muscles.

A lack of vitamin D, also known as vitamin D deficiency, can lead to osteoporosis (where the bones lose density and become more prone to breaks), or a condition called osteomalacia (where the bones become softened).

However in recent years, many experts have come to believe that vitamin D levels could be an important factor in several other conditions too.

Research has shown that vitamin D can play a significant role in the management of blood sugar and in reducing the risk of diabetes.

Studies have also suggested that adequate levels of vitamin D could help to reduce the risk of cardiovascular disease, high blood pressure, multiple sclerosis and rheumatoid arthritis.

Do I need to take a vitamin D supplement?

Persons who are at increased risk of vitamin D deficiency are advised to take a daily supplement. As mentioned above, at risk groups include children under 4, and those who do not get a lot of sun exposure (for instance if they cover much of their skin with clothing due to their cultural or religious beliefs, spend a lot of time indoors or are housebound.)

The general population over the age of five, including adults, pregnant or breastfeeding women and the elderly, are encouraged to consider taking a supplement which helps them meet the RNI of 10 mcg (400 IU) per day, all year round.

Many may be able to get all the vitamin D they need through sunlight alone during the summer months, and from their diet during winter. In such cases taking a daily supplement of 10 mcg may not be necessary, or only necessary during winter months.

If you’re not sure, make an appointment to speak to your doctor. They will be able to determine your current levels through testing if necessary, and advise you on the right amount to take.

Is there such a thing as too much vitamin D?


It’s unlikely that someone will exceed a safe limit through their diet and exposure to sunlight alone (although prolonged exposure to UV rays does carry other risks, so safe practices when out in the sun, such as using sun protection, should be observed).

However, it is possible to take too much vitamin D when taking supplements. Over time, this can lead to health issues and cause kidney or heart problems.

10 mcg per day is sufficient for the majority of people. Children aged 1-10 are advised not to exceed 50 mcg per day and adults not to exceed 100 mcg per day.

Where are vitamin D supplements available from?

Vitamin D supplements are widely available from pharmacies and health stores. Some lower strengths (to prevent deficiency) are available without a prescription, however higher doses (to treat deficiency) may require a prescription.

Those who are at increased risk of deficiency or who have certain medical conditions may be entitled to supplements for free via their local NHS services.

Fultium D3, a vitamin D supplement, is also available to buy from Treated.com. Those looking to buy this item or renew their prescription online can do so using our secure consultation facility. We also offer a simple repeat ordering service for those who have used our service before.