Causes of Vitamin B12 Deficiency
A long-term deficiency of Vitamin B12 can be extremely serious. Vitamin B12 works closely with folic acid to produce haemoglobin in red blood cells. It also plays a crucial role in DNA synthesis and proper nerve and brain function.
Some early-warning symptoms of Vitamin B12 depletion are tingling or burning sensation in the hands and feet, numbness and impaired mental function. However these signs may go unnoticed before a more serious problem develops.
Lack of Vitamin B12 can lead to a blood disorder called “Pernicious Anaemia” which may result in blindness and permanent damage to the nervous system. We definitely want to avoid getting to this point before addressing the deficiency!
What are the main causes of Vitamin B12 deficiency?
1) Nutritional Factors
Animal products are the only foods that provide significant
amounts of Vitamin B12. The
richest sources of Vitamin B12 are liver and kidneys. Fish, eggs, cheese and meat also contain good
amounts. There are no significant plant
sources. Some researchers claim to have
discovered Vitamin B12 in algae, seaweeds and fermented foods such as tempeh –
however now it has since been shown that what they found was not true Vitamin
People at risk of Vitamin B12 deficiency from nutritional factors include:
A vegan diet must be supplemented with Vitamin B12. The body is able to store Vitamin B12 and also has clever mechanisms for recycling it when there is a dietary lack – however eventually it will become depleted. It is particularly important to take Vitamin B12 supplements immediately on converting to a vegan diet, because it takes some time for the intestines to become more efficient in recycling. Calcium may also need to be supplemented. This mineral is necessary for Vitamin B12 absorption and is often lacking in vegan diets.
There is a high prevalence of Vitamin B12 deficiency in the elderly. Poor diet will be a factor in many cases however there is also a decline in the aging body’s ability to absorb and store nutrients.
Alcohol causes depletion of Vitamin B12 and many other vitamins and minerals. Over consumption of alcohol will impair liver and intestine function resulting in poor nutrient absorption
2) Problems of absorption
Vitamin B12 is a large molecule and a tricky thing for our intestines to absorb. The body has developed a sophisticated system for dealing with it. The stomach produces a substance called intrinsic factor that carries Vitamin B12 through the digestive tract for absorption in the lower part of the small intestine (ileum). The mechanism for absorbing Vitamin B12 may be affected by a variety of factors.
Surgery to remove part of the stomach or the ileum may result in impaired Vitamin B12 absorption.
Insufficient gastric acid. Vitamin B12 in food needs to be cleaved from its carrier proteins by the stomach acids. If for any reason there is an insufficiency of hydrochloric acid it will not be available for absorption. This situation may occur for many reasons, including long-term use of antacids and certain pharmaceutical drugs such was Metformin (a diabetic drug).Helicobacter Pylori bacterial infection of the stomach. This bacteria infects the stomach lining and may cause ulcers. Although H. Pylori infection is quite common and may cause no apparent symptoms it can prevent the production of intrinsic factor and thereby impair Vitamin B12 absorption.
Parasites such as tape worms.
Other chronic gastro-intestinal problems such as Crohn’s Disease.