According to Mount Sinai, a vitamin B12 deficiency can cause permanent nerve damage if left untreated. Two signs this is the case can appear in someone’s hands and feet; specifically, if they notice a numbness or tingling sensation.
This complication is reflected by the NHS who add that other complications can include:
• Vision problems
• Memory loss
• Pins and needles
• Loss of physical coordination
• Damage to parts of the nervous system
• Stomach cancer.
On stomach cancer, the NHS writes: “If you have a vitamin B12 deficiency caused by pernicious anaemia, your risk of developing stomach cancer is increased.”
Pernicious anaemia is one of several causes of a vitamin B12 deficiency alongside diet, conditions affecting the stomach or intestines, and medication.
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What is pernicious anaemia?
Pernicious anaemia is an autoimmune condition where the body’s immune system attacks itself; it is the most common cause of B12 deficiency in the UK.
How does it affect the stomach?
In the stomach, vitamin B12 combines with a protein known as intrinsic factor; this mix then allows the B12 to be absorbed into the rest of the body.
Pernicious anaemia causes the immune system to attack the cells in the stomach which produce this intrinsic factor; this means the body can no longer absorb the vitamin.
At the time of writing, scientists don’t yet know why pernicious anaemia occurs, but they do know women over the age of 60 are at greater risk from the condition, particularly if there’s a history of it in the family.
How is a B12 deficiency treated?
Each treatment will depend on what is causing the deficiency. In the case of diet, a GP may recommend boosting consumption of foods high in the vitamin, such as:
• Selected fortified breakfast cereals.
Should dietary changes not prove sufficient, injections of vitamin B12 may be prescribed. There are two types of B12 injection: hydroxocobalamin and cyanocobalamin.
On the timing of these injections, the NHS added: “At first, you’ll have these injections every other day for two weeks or until your symptoms have started improving.”
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How much vitamin B12 does the human body need?
The recommended daily dose for adults between the ages of 19 and 64 is around one and a half micrograms a day; a level which one should be able to maintain through the right diet.
However, this all depends on the diet. Someone who is vegan may not be able to get all the B12 they need and may need to use other means such as supplementation in order to obtain a healthy amount.
While it is possible to experience problems with health as a result of not consuming enough vitamin B12, there is less evidence about what happens if someone consumes too much.
The NHS writes on vitamin B12 overdoses: “There’s not enough evidence to show what the effects may be of taking high doses of vitamin B12 supplements each day.”
While the health harms of taking overdosing on vitamin B12 are unknown, what is known is the health problems which can arise as a result of overdosing on another common vitamin, vitamin D.
Vitamin D is the chemical the body produces when it is exposed to sunlight. While it is not possible to overdose on vitamin D from the sun, it is possible to overdose through supplements.
When this happens, a condition known as hypercalcaemia develops; this weakens the bones and damages the heart and kidneys.
The recommended dose for vitamin D in the UK for adults is 100 micrograms, however, the vitamin can also be found in oily fish, red meat, egg yolks, and liver.