The main signs of B12 deficiency are tiredness, shortness of breath and palpitations due to megaloblastic anemia. However, lack of this vitamin may also show itself as a sore mouth, weight loss, diarrhea or menstrual problems. If left untreated it can progress to irreversible nerve damage, in which case you may experience tingling or numbness, loss of co-ordination and memory loss.
A deficiency is also associated with an increased risk of heart disease and stroke, as without sufficient in the body, levels of homocysteine rise, which can damage the blood vessels. Although there are many sources of the vitamin in the diet – including meat, fish, eggs, dairy foods and items that have had B12 added to them – not everyone is able to absorb what they eat and some people have increased requirements. So, who is most at risk of developing an adequacy of vitamin B12?
Someone with one or more autoimmune diseases
One of the most common causes of this vitamin deficiency is due to pernicious anemia, which is an autoimmune disease – rather than simply attacking microbes and harmful cells, the immune system starts to attack its own tissues. In pernicious anemia the immune system damages the cells of the stomach that produce a substance known as intrinsic factor, which usually enables the body to absorb B12, so the uptake of the vitamin into the bloodstream is prevented, even though it might be in good supply in the diet; only three monthly B12 injections can solve the problem. Having one autoimmune disease places you at risk of having others; examples of these conditions include type 1 diabetes, psoriasis, rheumatoid arthritis, multiple sclerosis and celiac disease. However, older women with a family history of pernicious anemia are also at risk of developing it themselves.
Even if someone doesn’t have pernicious anemia, if their stomach does not produce sufficient hydrochloric acid, which is often the case as we age, they are unable to release the B12 attached to the protein in food, equally meaning they can’t absorb it. However, B12 shots are usually not necessary, as they can receive the benefit from taking either vitamin supplements or foods that have been fortified with vitamin B12, such as many breakfast cereals and soya milk.
Someone with an intestinal disease or surgery
As the vitamin is absorbed from part of the intestines known as the terminal ileum, any disease or surgery that affects this area can hinder its absorption and risk deficiency. Medical conditions where this might be an issue include crohn’s disease or celiac disease – even if pernicious anemia isn’t present – and relevant surgery might include a gastric bypass to aid weight loss or to remove a section of diseased bowel as in cancer. Here eating extra B12 foods won’t help, so again regular injections of the vitamin are required.
Strict vegetarians or vegans
As vitamin B12 only occurs naturally in foods of animal origin, those who avoid or severely restrict these in their diet are at risk of deficiency. Increasing the variety of their diet or including more vitamin fortified foods will help, as would taking a B12 supplement. Women who are pregnant or breastfeeding need to be aware that an inadequate intake of vitamins in their own diet can adversely affect their baby.
Someone with a high alcohol intake
Anyone who is dependent on alcohol is more likely to have a B vitamin deficiency. This in part relates to their increased requirements for B vitamins to metabolize the alcohol in their body, but alcoholics also tend to have a poor dietary intake, so they do not obtain sufficient from what they eat. Beating their addiction to alcohol and improving their diet will both help.
If you recognize some of the symptoms of B12 deficiency and you believe you fall into one of the at risk groups, a blood test will help to reveal whether this is the case. Adjusting your diet, taking supplements or receiving B12 shots will then help to prevent both the short and long-term complications of an inadequate supply.
Jake writes health articles mostly for UK health sites and blogs.