Our resident GP Dr Rangan Chatterjee, star of BBC One’s Doctor In The House, talks about the importance of vitamin D.

Vitamin D is arguably one of the most important vitamins for your health. It is critical for immune function, supple joints as well as your brain. You have specific receptors for vitamin D throughout your central nervous system as well as the hippocampus, which is an area of your brain involved with memory.

In 16 years as a doctor, I have seen lots of people with low vitamin D levels. In extreme cases, a deficiency can cause improperly formed bones, rickets in children and osteomalacia in adults. Suboptimal levels of the vitamin can also affect people in other ways. For example, I am seeing increasing numbers of people with aches and pains for whom painkillers and medications haven’t worked and yet taking a vitamin D supplement has reduced their pain, if not eliminated it completely.

 Love the outdoors

Often called the sunshine vitamin, D is produced when sunlight hits your skin. However, in the UK we can only make it between the months of May and October because that’s when UVB is strongest – this is the ray that’s responsible for vitamin D production. Your body only makes it if you’re not wearing sunscreen, but I’d still advise using sunscreen during the summer if you’re outdoors for long periods of time.

There are also genetic variations that can influence your ability to produce vitamin D. If you have darker skin, you will need more sunlight to make the same amount as someone with lighter skin.

And although your body won’t make vitamin D from the sun during winter, it’s still worth going outdoors; exposure to natural light helps regulate your body’s circadian rhythm so you sleep well, and being active is always good for your body, especially over winter when the tendency is to hibernate and move less.

Rangan’s vitamin D prescription

* Visit your GP for a vitamin D blood test. There are also plenty of private health practices that offer this for a fee.

* Over winter, ensure you eat oily fish (salmon, mackerel, anchovies) and eggs at least four times per week as they contain some vitamin D. Cod liver oil is another great source of vitamin D.

* Try to get some exercise outdoors each day during daylight hours.

* Use a high-quality vitamin D3 supplement each day. Look for one that contains D3. You will likely need at least 1000 IU per day but this can be tweaked according to your own blood results.

If you have a question for Dr Chatterjee, email us at topsante.talkback@kelsey.co.uk. Find out more at drchatterjee.com.