Vitamin B12 is used by the body to keep the nervous system healthy, according to the NHS.
It’s also used to make red blood cells, as well as to help with the production of DNA.
You could be at risk of a vitamin B12 deficiency if you regularly have headaches, fatigue, and a loss of appetite.
One of the more “peculiar” symptoms of a deficiency is having white spots in the skin, according to charity Thyroid Patient Advocacy.
Patients that need more vitamin B12 in their diet may develop white spots in their skin, due to a lower level of melatonin, it said.
The spots are most likely to appear on the outside of the forearm, and they can become very dry and flakey.
But, just because you have white spots in your skin, it doesn’t necessarily mean you have a vitamin B12 deficiency.
“White spots in the skin, resulting from melatonin becoming absent in the area [could be a sign of vitamin B12 deficiency],” said the charity.
“These often occur on the outside of the forearm, but may occur in other places. The longer these spots are there, the whiter they get.
“As time goes by, the spots become very dry and flaky to the extent that small raw spots of skin may be exposed.”
Another warning sign of the condition is having an itchy or tingly tongue, it added.
The tongue may become itchy from time-to-time, completely without warning.
The edge of the tongue is usually affected, either along one side or at the tip.
Some patients’ tongues can string, or become very painful instead of itchy.
Other vitamin B12 deficiency symptoms include shortness of breath, having an eye twitch, or having sores at the corners of the mouth.
The deficiency may be caused by pernicious anaemia. A condition where the immune system attacks healthy stomach cells.
See a GP if you’re worried that you may have a vitamin B12 deficiency.
You could top up on vitamin B12 by eating more beef, liver, salmon, egg or dairy foods.
Most cases can be easily treated with vitamin B12 supplements and diet changes.
It’s important for the condition to be diagnosed early, as it can lead to heart conditions and temporary infertility on rare occasions.