Those following a vegan lifestyle increasingly know they must supplement with vitamin B12. But how many who suffer with Irritable Bowel Syndrome; take metformin to lower blood sugar levels or antacids to tackle heart burn realise they too could need to follow suit?
Given that too little of this vitamin can leave you exhausted, depressed and confused; reduce concentration, cause temporarily infertility in woman, and ultimately lead to permanent nerve damage, it’s a nutrient that’s well worth taking seriously. Here’s who needs to take note…
Vegans: Vegetables, fruits, grains and other plant foods don’t contain B12, so if you are switching to or following a vegan lifestyle, the Vegan Society recommends taking either at least 10 micrograms a day or at least 200 micrograms weekly. If you have been vegan for a while, it is worth asking your doctor to check levels with a blood test. If found to be deficient, your GP or a nurse will give you B12 injections, usually every other day for 2 weeks or until your symptoms have started improving. After this, B12 tablets are likely to be prescribed twice daily between meals and once levels are normal in your blood, a daily supplement will be necessary for life.
Irritable Bowel Syndrome (IBS): But it is not just vegans who need to take care, as Professor Anastassios G. Pittas, of the Tufts University Medical School points out. People who have IBS and other inflammatory bowel diseases like Crohn’s as well as Coeliac Disease are also at increased risk of B12 deficiency. This is because B12 is normally absorbed in the end part of the small intestine, an area often damaged by such conditions. People who have had parts of their bowel removed or bariatric surgery may also be affected, making on-going monitoring of this nutrient vital.
Type Two Diabetes: For anyone prescribed the medicine metformin, to help control blood sugar levels, it is worth knowing that it interferes with absorption of vitamin B12. “Those taking Metformin risk deficiency at around double the rate compared to patients not being treated with this drug” explains Pittas. “The longer the duration of metformin use, the higher the likelihood of developing vitamin B12 deficiency”, which is why he checks his patients’ B12 levels when they start taking Metaformin; one year into treatment and every three years, thereafter. “I check more often if there are additional risk factors such as vegan diet or history of bariatric surgery.” Although only recommending vitamin B12 supplements when blood tests show a deficiency, Pittas urges all patients on metformin to hit their daily recommended intakes of calcium, which in the UK, is 700mg. This is because calcium reduces Metformin’s blocking effect on B12 absorption. Calcium-rich foods include milk and calcium fortified dairy alternatives, plus canned oily fish eaten with their bones like sardines. Other foods give us calcium too, such as almonds, dark green leafy vegetables and tofu along with sesame seeds, dried figs and apricots and pulses including baked beans and chickpeas.
Heartburn, Stomach Ulcers and Indigestion: When diagnosed with any of these conditions, you may be prescribed protein pump inhibitors and H2-receptor antagonists, to help lower stomach acid. While these drugs can help to solve symptoms, in the long-term, they also interfere with absorption of B12. Professor emeritus Irwin H. Rosenberg of the Tufts Friedman School explains: “Stomach acid is needed to release B12 from the food we eat and medications that lower stomach acid production may reduce the amount of B12 available for absorption.” It can take a year before B12 levels in the blood are significantly affected and according to the American Gastrointestinal Association, although these drugs may not lead to clinical deficiency by themselves, when combined with other risk factors like also taking Metformin, being over 60 years of age, or following a vegan lifestyle, they could together trigger deficiency.
50 Years Plus: Our bodies find it harder to absorb dietary forms of B12 as we move through the decades. In part, this is because we have less hydrochloric acid in our stomachs, needed to help separate out this vitamin from the protein it is attached to in food when we eat it. This is the case, independent of any other absorption issues and begins in our 50's. Once we reach 65 years of age and up until 74, one in 20 people are affected by B12 deficiency. By 75 and over, this figure rises to one in ten. This can cause extreme tiredness, affect the ability to think clearly, exacerbate confusion and low mood as well as even sparking psychotic disorders. Accurate diagnosis and treatment with supplements (B12 is more easily absorbed from supplements than food), and / or injections prescribed by your medical team can catch deficiencies in their early stages and restore blood levels of vitamin B12 and help to improve quality of life.
NB. Always tell your doctor, Registered Dietitian or Registered Nutritionist which supplements you are taking or intend to take when you consult with them. People with pernicious anaemia are unable to make 'intrinsic factor' and have problems absorbing vitamin B12 from foods or supplements. Pernicious anaemia needs to be managed by your GP.
