THE HIGH RISK OF B12 DEFICIENCY
What do vegans, obese people & alcoholics have in common?
What do the following five groups of people have in common?
• consuming a purely vegan whole food diet
• having gastric bypass surgery (e.g. for the treatment of obesity)
• being over the age of 50
• taking antacids to treat stomach ulcers, hiatus hernia, indigestion
• suffering from alcohol dependency.
Essentially, they all contribute to vitamin B12 deficiency and if you said ‘yes’ to more than one of the above, you have a VERY HIGH risk of being B12 deficient.
Why is vitamin B12 so important? 1. Vitamin B12 is found naturally only in animal foods.
It is found particularly in fish (especially shellfish), crab, caviar, dairy, liver, meat and poultry. Animals store B12 in their liver and muscles and may pass varying amounts into their eggs and milk. Duck eggs provide 10 times more B12 than chicken eggs. Goose eggs provide 20 times more B12 than chicken eggs (just in case you have access to them). Faeces is also a rich source of B12 hence rabbits, dogs and cats sometimes eat faeces. But let’s not go there.
2. Vegans need synthetic B12 in fortified foods or supplements.
Sources of B12 for vegetarians include milk, cheese, yoghurt, eggs, some yeast extracts and fortified products like tofu, soy and breakfast cereals. If buying fortified foods, read labels to avoid added sugar. Cheeses contain varying amounts of B12 with Swiss, Mozzarella and Feta being good options (in that order).
3. B12 needs to be released from food before it can be absorbed.
B12 is unique among the B vitamins in that it can be stored in the liver for up to two years. This is good news. All other B vitamins require consistent daily intake. However, B12 absorption requires adequate amounts of two substances that tend to decline with age: stomach acid and ‘intrinsic factor’ (IF). Intrinsic factor is secreted by parietal cells in the stomach and it ‘unlocks’ B12 from food. In other words, B12 needs to be released from food before we can absorb it.
As we age, the stomach tends to produce less acid and less intrinsic factor, thus reducing our absorption of B12 even if we appear to be eating adequate amounts. Thirty percent of people over the age of 50 have reduced absorption of B12. Excessive alcohol consumption leads to inflammation and disruption of the stomach lining impairing our ability to absorb B12. Similarly, gastric bypass surgery decreases stomach volume and along with it, stomach acid and IF. Hence the five groups listed at the start are at risk of B12 deficiency. However, synthetic B12 is already in free form & doesn’t require stomach acid for absorption.
What is the recommended daily dose of B12?
About 2.4 micrograms (mcg) per day. One serving of fish (salmon, mackerel, tuna, trout, etc.) provides adequate daily needs. If you eat a diet that includes a selection of the above-mentioned B12-containing foods, you will be consuming sufficient amounts.
You will need more than 2.4 mcg if you are pregnant or breastfeeding (2.7 mcg) or have an under-active thyroid, drink a lot of alcohol, take antacids, have had stomach surgery or are over age 50. Certain medical conditions such as coeliac or Crohn’s disease can make it very difficult to absorb B12 from food. In these instances, you will need to take supplements on a regular basis. There is no official upper limit of B12 intake because you will get rid of any excess in your urine.
In the next issue of Great Health GuideTM, I will discuss the essential role that B12 plays in proper functioning of the brain and nervous system, in the formation of red blood cells and in metabolism of carbohydrates, proteins and fats.
Dr Helena Popovic is a medical doctor, leading authority on how to improve brain function, international speaker and best-selling author. Helena runs weight management retreats based on living not dieting, and is the author of the awardwinning book ‘NeuroSlimming – let your brain change your body’. For more information, refer to Helena’s website.