Vitamin D is a fat-soluble compound produced in the body through the action of sunlight. Falling short of the required amount could weaken immune defences, but if low levels are left untreated, discomfort may also arise. One sensation in the hands and feet could be signalling an underlying deficiency.
Vitamin D insufficiency is also associated with numbers, loss of feeling and pain in the arms and feet.
The NHS says: “A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults.”
What’s more, vitamin D helps the body absorb the right amount of phosphate and calcium, both of which are important for building and repairing bones.
Steve Jones, emeritus professor of human genetics at University College London (UCL), told The Times: “[Vitamin D] is unique from all other vitamins, which just fill a gap in some pathway in the body, taking part in biochemical reactions.
“Vitamin D actually controls many of the functions of the body: from the lungs to the heart to the brain, you’ll find vitamin D hard at work.”
Sources of vitamin D
As cases of flu risk soaring during the winter, keeping the body’s immune system in good condition is more important than ever.
People usually make enough vitamin D during the summer through exposure to sunlight.
In the winter, however, vitamin D has to come from food, and it can be difficult to ingest the recommended amount.
“From about late March/early April to the end of September, most people should be able to make all the vitamin D they need from sunlight,” explains the NHS.
“But from October and early March, we do not make enough vitamin D from sunlight.”
During the winter months, individuals can source their vitamin D from oily fish, red meat, liver, egg yolks, and fortified foods.
“In the UK, cow’s milk is generally not a good source of vitamin D because it is not fortified, as it is in some other countries,” adds the health body.
Dietary supplements are sometimes prescribed to those who are deficient.
Over-supplementation of vitamin D, however, can be just as harmful and should be avoided.
In the past year, health bodies have urged the general public to top up their vitamin D levels.
In fact, last year vitamin D supplementation was recommended to fortify immune defences against coronavirus through the winter.