National Vitamin D Day: Everything You Need To Know About The 'Sunshine Vitamin'

2 November is National Vitamin D so we spoke to dietician Nichola Ludlam-Raine to get the low-down on 'the sunshine vitamin'.

In my role as a dietitian I regularly see blood results of patients before undergoing hospital procedures and the majority are indeed vitamin D deficient (perhaps it’s because I live ‘up north’ too!) and as a result it is often at the forefront of my mind. Although many people are not deficient in vitamin D, most do not have an optimal level of vitamin D either.

I personally take a 10 mcg of vitamin D all year round, making sure that I take it daily particularly from October to March.

What is Vitamin D?

Vitamin D is often known as the 'sunshine vitamin' as it’s made under the skin when exposed to the sun. Vitamin D is not actually a vitamin, it’s a hormone, and a lack of vitamin D can cause children to develop rickets (bone deformities) and adults to develop osteomalacia (weak bones).

What does Vitamin D do in the body?

Vitamin D is responsible for helping the body to absorb calcium, a mineral essential for healthy bones and teeth. Vitamin D may also play a role in the health of our immune system, mood and cognitive function.

Where do we get Vitamin D from?

Although most of the vitamin D we get is from the sunshine, it is found in a small number of foods including; oily fish such as salmon, mackerel and sardines, eggs, and fortified spreads and breakfast cereals. Regarding sun exposure, in the UK the UV light is only strong enough to make vitamin D on exposed skin from around 11am to 3pm from April until September. It is recommended to expose your skin to the sunshine two or three times a week for at least 15 minutes (before applying sunscreen), however it is not known if this amount is sufficient to maintain optimum levels of vitamin D during the winter months due to the number of factors that affect vitamin D production in the skin.

If you use Lumie bright lights to treat SAD or simply as an energy boost you should still think about taking extra Vitamin D. Lumie lights emit just a tiny amount of UV so it's not the same as soaking up some real rays and won't help your Vitamin D production.  

Who is at risk of Vitamin D Deficiency?

Groups of the population at risk of not making enough vitamin D in the body include pregnant and breastfeeding women, babies and young children under the age of 5, people aged 65 and over, people who cover up their skin when outside or who stay indoors for long period and people who have darker coloured skin.

 Who needs a Vitamin D Supplement?

Between the months of October and April, everyone in the UK should consider taking a supplement containing at least 10 mcg of vitamin D.

The Department of Health also recommends that all pregnant and breastfeeding women should take a daily supplement containing 10 mcg of vitamin D a day and all babies from birth to 1 year of age should be given a daily supplement containing 8.5 to 10 mcg of vitamin D in the form of drops (babies who are fed infant formula do not need supplements until they are receiving less than 500ml of infant formula a day). Children aged 1 to 4 years old should be given a daily supplement containing 10 mcg of vitamin D.

Vitamin D3 (cholecalciferol) supplementation is recommended over D2 (ergocalciferol) supplementation as the D3 is used more effectively in the body. In addition to this, vitamin D is fat soluble, which means that it should be taken with a source of fat such as peanut butter, olive oil or oily fish to help with absorption. If your vitamin D supplement comes as an oil-based capsule though (rather than a dry tablet), you can take this at any time of day.

Nichola Ludlam-Raine (née Whitehead) is a Specialist Registered Dietitian BSc (hons) PG Dip MSc RD. For more info about Nichola, tips on nutrition, weight management and overall wellbeing, head to her website nicsnutrition.com.