B-12 deficiency is shockingly widespread. Studies now show that up to 40% of the population may be deficient in vitamin B12.
* Chest pain or shortness of breath
* Fatigue or unexplained weakness
* Dizziness, trouble with balance, and fainting
* Confusion, memory loss or dementia
* Coldness, numbness or tingling in the hands and feet
* Slow reflexes or diminished nervous system function
* Pale skin or yellowing of the skin
* Sore mouth and tongue
… in addition, vitamin B12 deficiency can actually cause brain shrinkage, according to a University of Oxford study [REF]. Although more work needs to be done, research is already suggesting a link between vitamin B-12 deficiency and Alzheimer’s.
This video shows how several doctors almost died (and are permanently damaged) by vitamin b12 deficiency, one of them even a doctor who failed to diagnose his own vitamin b12 deficiency, originally believing it a “hoax”. This led to permanent nerve damage. Don’t make this mistake!
What does vitamin B12 do in the body?
Low vitamin B12 can be a problem for anyone.
Our bodies need B12 to make red blood cells and nerves. A severe deficiency can lead to anaemia, depression and memory loss. It can cause incontinence, loss of taste and smell, headaches, migraines and more.
But for women, low B12 levels have also been linked to one of the most serious epidemics of modern times: breast cancer.
A study from Johns Hopkins University tells the whole story. Researchers compared blood samples of 195 breast cancer patients with 195 healthy women. The women with the lowest levels of B12 had four times the risk of breast cancer as those with the highest levels. 
How can this be? Well, vitamin B12 makes sure that your DNA gets copied accurately when cells divide. It’s critical to prevent the kind of DNA damage that leads to breast cancer.
How Vitamin B12 Helps Prevent Breast Cancer
Our cells are constantly dividing and replicating themselves. DNA strands have to unravel, make a copy of our chromosomes, and zip up the DNA again. This process happens billions of times every day. There is the potential for a lot of it going wrong.
Vitamin B12 is one way your body makes sure everything runs smoothly. It helps convert the amino acid homocysteine to methionine and then to S-adenosylmethionine (SAMe). This natural compound triggers the “methylation” process of making well-formed DNA.
When you have (even just slightly less) vitamin B12 than required, i.e. a (small) deficiency, DNA in new cells can have weak links between chromosomes. And that makes cells more likely to form mutations linked to cancer. 
But you can reverse the slide to cancer even after these mutations occur. A study in the famous Journal of the American Medical Association found that taking vitamin B12 and folic acid (vitamin B9) makes the difference. It not only stops the progress of precancerous changes but also helps reverse the damage. 
This is why enlightened doctors encourage women to ensure they are getting enough vitamin B12. Many women are simply NOT getting enough B12, because they have followed low-fat diets in their efforts to lose weight and thus have cut back on fatty meats, fish, dairy and eggs.
Unfortunately, low-fat diets are a big cause of vitamin B12 deficiencies. You can only get B12 by eating a primal diet rich in animal products. This is because vitamin B12 is only produced in the gut of animals. You simply cannot get it from plants.
Some of the best food sources of vitamin B12
Type of Food
|Liver, beef, braised, 1 slice||
|Clams, 85g / 3 oz.||
|Trout, rainbow, wild, cooked, 85g / 3 oz.||
|Salmon, sockeye, cooked, 85g / 3 oz.||
|Trout, rainbow, farmed, cooked, 85g / 3 oz.||
|Beef, top sirloin, broiled, 85g / 3 oz.||
|Yogurt, plain, 235g / 1 cup||
|Haddock, cooked, 85g / 3 oz.||
|Tuna, white, 85g / 3 oz.||
|Milk, 240ml / 16 tablespoons / 1 cup||
|Cheese, Swiss, 28g / 1 oz.||
|Egg, large, 1 whole||
|Chicken, roasted, ½ breast||
B12 from vegetarian sources?
Some dieticians claim you can get B12 from plant sources, such as seaweed, fermented soy, spirulina and brewer’s yeast. In reality, these foods only contain analogs of B12 called “cobamides”. Cobamides can block your intake of B12 and increase your need for the real thing. 
Why women need to supplement vitamin B12
We have seen how vitamin B-12 deficiency is especially common in vegans and vegetarians because typical vitamin B12 sources (meats, yoghurt, etc.) are simply not present in their diets.
But even meat eaters eating B12 foods several times a day may be deficient in B12 due to poor digestion, particularly older people who suffer a diminished ability to absorb nutrients in their small intestine.
Vitamin B12 can only be absorbed in the small intestine, and due to common intestinal ailments, absorption can be blocked. Vitamin B12 deficiency can be caused by low stomach acid and heavy alcohol use. Drugs like proton pump inhibitors (Prilosec and Nexium) interfere with B12 and so do diabetes drugs like metformin or pain pills. Moreover, intestinal parasites can also strongly block its absorption in the gut. 
Because of all this, many women (in particular) need to supplement vitamin B12. According to the National Institutes of Health, most adults need just 2.4 mcg per day. But women may need to take much more than that.
According to Dr Al Sears, women should take 100 mcg vitamin B12 per day. However, he advises many of his patients to take as much as 2,000 mcg per day. He claims that this is safe because “the body excretes any excess or stores it in the liver for later use”.
How to choose the right vitamin B12 supplement for you
I have written a whole post on this!
You can read my current vitamin B 12 supplementation recommendations here
Tags: vitamin B12, women, breast cancer, fatigue, shortness of breath
1. Wu K, Helzlsouer KJ, Comstock GW, et al. “A prospective study of folate, B12, and pyridoxal 5-phosphate (B6) and breast cancer.” Cancer Epidemiol Biomarkers Prev 1999;8:209-17.
2. Feinberg AP, Vogelstein B. “Hypomethylation distinguishes genes of some human cancers from their normal counterparts.” Nature, 1983;301:89-92.
3. Heimburger DC, Alexander C, Birch R, Butterworth CE, Jr, Bailey WC, Krumdieck CL. “Improvement in Bronchial Squamous Metaplasia in Smokers Treated With Folate and Vitamin B12: Report of a Preliminary Randomized, Double-blind Intervention Trial.” JAMA. 1988;259(10):1525-1530.
4. Watanabe F et al, “Pseudovitamin B(12) is the predominant cobamide of an algal health food, spirulina tablets.” J Agric Food Chem. 1999;47(11):4736-41.
6. Diagnosing vitamin b12 deficiency on youtube: