Pernicious anemia ~ what is it?

(This is a brief description only.)

What is Pernicious Anemia?

Pernicious anemia is a type of anemia whereby the red blood cell production is compromised because of a deficiency of Vitamin B12 (cobalamin). Quite simply in my best street lingo: they get all big and wobbly, they’re referred to as “macrocytic”: macro = big, cytic = cell. Big ass silly cells not doing their job properly.

Vitamin B12 (along with Vitamin B9 [folate] and iron) is an essential nutrient required for the production and function of healthy red blood cells.

Deficiency of Vitamin B12 is caused either by a corresponding deficiency of intrinsic factor* or the autoimmune destruction of intrinsic factor (and dietary insufficiency).

*Intrinsic factor is a protein/hormone secreted by cells of the stomach which assists the absorption of Vitamin B12 from the inside of the small intestine across into the blood stream in order to participate in red blood cell production.

Basically, intrinsic factor pairs up with Vitamin B12 and takes it across the intestinal membrane. It’s a transport protein. Vitamin B12 cannot be absorbed without intrinsic factor.

  • In those with autoimmune pernicious anemia, the cells of the stomach which secrete gastric acid are damaged, which prevents liberation of Vitamin B12 from foods to begin with.
  • Over time intrinsic factor also stops being secreted and/or destroyed: an antibody binds to intrinsic factor preventing it from binding with Vitamin B12.
  • In those with diseases that significantly interfere with digestion or those who have undergone substantial gastric surgery, interference to absorption and/or the lack of secretion of intrinsic factor is the underlying cause.
  • Age takes its toll on the function of the gut too.

The thing is that as Vitamin B12 is stored really well in the liver, it can take many years for stores to run dry and for deficiency signs and symptoms to present.

Tell me more about this Vitamin B12?

As well as participating in the production and function of red blood cells, Vitamin B12 is a co-factor for a very important reaction in the synthesis of DNA and RNA (methylation [donation of a methyl group] to be precise) and neurotransmitters.

As such, the central nervous system can be profoundly affected by a deficiency of Vitamin B12 (treatment for depression can include Vitamin B12 supplementation).

Further, the relationship between elevated levels of homocysteine and cardiovascular disease in part may be attributed to a deficiency of Vitamin B12 as it participates in the methylation reaction that converts homocystine to methionine.

Vitamin B12 is an important little guy!

Am I at risk, what do I have to eat?

Well this is the part where vegetarians get sad because it’s only found in animal foods: highest in liver (of course, it stores there!) as well as other organ meats, muscle meat, seafood, dairy and eggs.

As such, strict vegetarians and vegans are advised to supplement with Vitamin B12 in order to prevent deficiency. Or fortified vegetarian/vegan foods can be consumed. Vegan supplements are derived from bacteria.

Recommended daily intake for healthy adults is about 3mcg, that’s micrograms, not milligrams. It’s not required in large amounts. But it is required daily in order to sustain long term stores.

If you eat meat, dairy and eggs and don’t have a history of gastric surgery or digestive disease then you’re sweet, really.

If you are a long term strict vegetarian/vegan and don’t supplement or eat fortified foods you’d be wise to get your B12 levels checked (or better still, homocysteine levels) and take action accordingly depending on results.

If you’re a breastfeeding mother who is also a vegan then likewise for your bubba.

Remember it takes years for deficiency to present owing to liver stores so if you’re a recently switched up vegetarian/vegan then I’d even suggest having stores checked now (request your pathology results, always!) for a reference point in the future.

Do visit a very good health food store or see your practitioner for supplement recommendations.

As an idea for meat and dairy eating folk, here are some measures of Vitamin B12 in foods:

  • 1 x egg: 0.6mcg
  • 1 x 200g piece beef: 2.7mcg
  • 1 x cup chopped roasted chicken: 0.5mcg
  • 1 x fillet perch: 1.1mcg
  • 1 x fillet mackerel: 9.8mcg (WIN for the oily fish!)
  • 1 x cup full cream milk: 1.1mcg
  • 1 x slice cheddar (about 30g): 0.2mcg
  • 1 x cup full cream yoghurt: 0.9mcg
  • 1 x slice of beef liver (about 70g): 48mcg
  • 1 x 85 tin tuna, canned in water: 2.5mcg

What are the signs and symptoms of pernicious anemia?

The common signs are much like what you’d expect from anemia: tiredness, breathlessness. And this could be accompanied by moodiness owing to the central nervous system missing out on it’s methylation reactions to make neurotransmitters.

Click here for a comprehensive guide: Pernicious anaemia society symptom list.

Special note: many vegetarians eat adequate Vitamin B9 (folate) sufficient for their red blood cells to divide and as such, Vitamin B12 deficiency anemia may be undetected (masked) when investigated. Better still to have homocysteine levels checked.

Yours in un-wobbly blood cell love, K180, x



Pernicious Anaemia Society

World’s Healthiest Foods – Vitamin B12.

Higdon, J. An Evidence-Based Approach to Vitamins and Minerals. 2003. Thieme, NY.

Hoffer A, Prousky J. Naturopathic Nutrition. 2006. CCNM Press, Canada.










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