By Rosa Monserrat Amengual

Why is vitamin D so important for our health and is it common to be deficient?

Vitamin D helps support the normal function of the immune system. Vitamin D also helps regulate the amount of calcium and phosphate in the body. These nutrients are needed for normal growth and development of bones, teeth and muscles. There are two sources of vitamin D, sunlight and diet. During summer months, most people can get adequate vitamin D from sunlight (five-10 minutes unprotected exposure to sun) and a balanced diet. In the UK, sunlight doesn’t contain enough UVB radiation in winter for our skin to be able to make vitamin D. Public Health England recommends taking 10mcg of vitamin D during winter months. Dietary sources of vitamin D in the UK are natural food sources, fortified foods and supplements. Foods that contain significant amounts of vitamin D include oily fish, egg yolks, liver, fortified cereals, meat and fat spreads.

What signs may we experience if we have low levels and why is this more common during the winter?

During the winter months (October to March), the sun’s ultraviolet rays are not strong enough for the body to synthesise into vitamin D. Low levels of vitamin D have been linked to an increased risk of your immune system not having a normal function, as well as not normal development of bone and tooth.

Do you recommend a supplement and if so, what levels and quality should people look for?

During autumn and winter, everyone (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10mcg (400IU) of vitamin D. Breastfed babies from birth to one year of age should be given a daily supplement containing 8.5-10mcg of vitamin D. In some cases, it is recommended supplementation containing 10mcg (400IU) all year round (people who spend little time outside and people who wear clothes that cover up most of their skin when outdoors). Eating foods rich in vitamin D and spending time outside in sunshine and taking a supplement of vitamin D is not a problem. Food supplements should not be used instead of a varied, balanced diet and a healthy lifestyle.