1 – Being vegetarian or vegan
Vegetarians and vegans are at risk because plant-based diets contain very little natural vitamin B12, which is mostly found in meat. Pescatarians also tend to have diets low in vitamin B12.
2 – Alcohol
Drinking too much booze causes a list of problems as long as your arm. Near the top of the list is damage to the stomach lining, leading to reduced absorption of vitamin B12 – among many other nutrients! Alcohol can also interfere with the liver’s ability to store and activate B12.
3 – Getting older
Older adults are more prone to B12 deficiency due to reduced stomach acid production and changes in diet.
4 – Smoking
Many smokers have the symptoms of B12 deficiency. Why? Cigarette and vape smoke contains lethal cyanide, and your body uses up vitamin B12 to detox it safely. This means you could eat plenty of B12 in your diet, but smoking uses it up so there’s less left for all the other important jobs it does in the body.
5 – Certain medicines
If you take a proton pump inhibitor (PPI) to treat stomach ulcers, acid reflux (GERD) or a hiatus hernia, you may not be absorbing enough vitamin B12. Your stomach needs to be at just the right acidity to take up this important vitamin, and these medicines can make your stomach too alkaline for the process to work.
Metformin for pre-diabetes is another medicine which can block your uptake of B12.
Certain antibiotics may also affect B12 levels.
Anticonvulsants for epilepsy can reduce B12 absorption.
6 – Illnesses that reduce B12 absorption
Other problems in either the stomach or the intestine can also stop the B12 absorption process from working. These include:
- Atrophic gastritis, which causes the stomach lining to get too thin so it cannot produce enough intrinsic factor.
- Disease in the small intestine, including Crohn’s disease, celiac disease and SIBO (Small intestinal bacterial overgrowth).
- Gastric bypass surgery, which removes part of the stomach.
- Chronic pancreatitis, which can affect the release of pancreatic enzymes needed for B12 absorption.
Various long-term illnesses can affect nutrient absorption, and also increase our need for specific nutrients as our bodies work constantly to deal with the effects of the illness. HIV/AIDS erodes our levels of vitamin B12 amongst other nutrients. Chronic kidney disease (CKD) or liver disease can also reduce B12 storage and metabolism.
7 – Pernicious anaemia
Vitamin B12 is mostly absorbed in the last part of the small intestine. However, we can only absorb it if it’s first bound to a protein molecule called intrinsic factor, which is made by special cells in the stomach called parietal cells.
An autoimmune disease called pernicious anaemia causes vitamin B12 deficiency by destroying “intrinsic factor”.
8 – Genetic factors – which are fairly common
Some people have genes that make them less efficient at activating and using vitamin B12. Whilst not strictly a deficiency, the result is the same. These include MTHFR gene mutations, for example. Some of these genes affect about 10% of the population, whilst others are so common they are found in almost one third of us.
9 – Parasites from your holiday
Oh yes, it’s not always sunburn or the trots! Tapeworm infections are another holiday souvenir for some people. They come from infected meat and consume B12 in the intestines (along with many other nutrients), leading to deficiency. Other worm infections that you can catch on holiday, from fish for example, can also get in the way of absorbing vitamin B12.
10 – Pregnancy and Breastfeeding
You need more vitamin B12 than usual when you are pregnant or breastfeeding. If you don’t ramp up your intake, your baby will take all he or she needs, whilst you could become deficient.
How to fix a Vitamin B12 deficiency
- Eat more meat, especially red meat.
- Give up smoking.
- Cut down on alcohol as much as you can.
- See your doctor if you have tummy issues which might be more effectively managed, or cured.
- Take a methylated vitamin B12 supplement. This will contain methylcobalamin and adenosylcobalamin, the two forms that are ready for your body to use.
