Vitamin D is essential for our bone health. Lack of vitamin D is the cause of rickets in children, and it can cause ‘thinning’ of the bones in adults, increasing the risk of injuries such as wrist and hip fractures. It may also play a part in maintaining cardiovascular health and reducing the risk of neurological conditions such as dementia, but the evidence for this remains unclear.
Up to a quarter of the UK population is deficient in vitamin D, with rates higher in older adults and up to 94% in adults of south Asian extraction. Most people do not experience any symptoms, but deficiency can cause pain and muscle weakness.
Vitamin D is largely made by the skin when it is exposed to sunlight, it is also present in some foods including oily fish, some breakfast cereals and dairy products.People at higher risk of vitamin D deficiency include those who are not exposed to enough sunlight, people with darker skin, children, pregnant ladies and people taking certain medications such as corticosteroids.
It does not take much sunlight for the skin to produce enough vitamin D, in the region of 15 minutes daily (without sunscreen) will be fine for most of us. Unfortunately in the UK, however, we tend not to have enough sunshine apart from a few months over the summer. If you are worried Vitamin D levels can be checked with a blood test, but this is not necessary for most people.
NICE advises that all adults and children take a vitamin D supplement all year round to develop and maintain good bone health. Suitable preparations for adults and children can be obtained over the counter from any pharmacy.
Taking a maintenance supplement of vitamin D is safe and I would recommend it all year round for young children, pregnant and breastfeeding ladies, people with darker skin and those who rarely go outside (such as nursing home residents). For people with fair skin who are outdoors a lot over the summer I think taking a supplement only during the winter is reasonable.
It is also important to ensure adequate dietary calcium intake, the main source of this being dairy products. If intake is insufficient then calcium supplements may be advised, these should be prescribed and monitored by your doctor.
I hope that as we head into the darker months this is helpful!
Dr Marcus Gleave