Vitamin B12 - You Need It
Vitamin B12 is a strange one - essential for making proteins, enabling blood cells to carry oxygen, vital for energy and essential for making DNA, building nerves and the brain - yes, it's pretty damn important. Yet, insufficiency is quite common, particularly amongst vegetarians and vegans as well pregnant women and especially those over 60.
One of the challenges with B12 is that even if we consume foods that contain it, it has to combine with a stomach secretion called intrinsic factor to be absorbed and some people just don't produce enough intrinsic factor and are prone to pernicious anaemia which is one cause of B12 deficiency.
Because of likely insufficiencies, particularly as you get older, it is one of those vitamins that you should seriously consider supplementing. One of the key effects B12 has is to reduce the levels of the critical marker, homocysteine*, down. High levels of this marker are strongly corelated with numerous diseases including brain shrinkage and dementia.
B12 is a tricky beast and some foods contain 'false' B12 as it is in a form that is unable to bind to intrinsic factor in the stomach and so is not absorbed.
For the omnivores, B12 is found naturally in liver, red meat, poultry, game, oily fish, eggs and dairy products (especially ferments - yoghurt and kefir). It's a little trickier for those following an exclusive plant based diet as there are few natural plant based sources and supplementation and consuming B12 fortified foods is important. Again, as we get older supplementation has an important role.
Of the plant-based sources, the most effective are certain mushrooms (notably shiitake), blue/green algae (think chlorella and spirulina), nori seaweed and sea buckthorn which is a plant that grows close to the sea. However, consuming these foods can be a little hit or miss as the reality is that B12 doesn't naturally occur in these plants but rather through bacterial contamination or more precisely a symbiotic relationship between the plant and bacteria. This hit and miss approach has led to the Vegan Society recommending to either supplement B12 or eat foods fortified with B12, rather than depend on plant foods that supposedly contain B12.
However, it is not that we need much B12. For plant-based diets and those moving towards 60 a supplement of 20mcg is recommended to prevent deficiency. Many multi-vitamin supplements will only provide 2.5mcg so it is well worth considering a targeted B12 or B complex supplement.
*Homocysteine is an amino acid found in the blood. Elevated levels of homocysteine have been associated with narrowing and hardening of the arteries, an increased risk of heart attacks, strokes, blood clot formation and Alzheimer’s disease.
