Current Issue

A lack of vitamin B12 can make you anemic, cause nerve damage and psychiatric abnormalities, and even raise your risk of heart disease. When did you last have your levels checked?

Deficiency problems

In the early stages, vitamin B12 deficiency may cause numbness, tingling, poor balance, or fatigue. Fortunately, these are all reversible. It’s the long term lack of B12 that’s a serious cause for concern, since it can lead to irreversible brain damage.

An inadequate diet is one common reason for low levels of B12, especially among vegans and vegetarians. However, approximately 95 percent of the cases of B12 deficiency occur among people who cannot absorb this vitamin into the body at all or have a reduced ability to absorb it. People are at particular risk who are over the age of 50 or who are taking metformin for diabetes or pre-diabetes.

Where to get B12

Very small amounts of vitamin B12 can be produced in the mouth and colon, but these are either insufficient to meet the daily requirement or too far down in the intestinal tract to be available for absorption, which occurs in the small intestine. Vitamin B12 needs to come regularly from either food, supplements, or injections.

  • Food: Animal products such as eggs and dairy can supply B12. Vegans need to use fortified plant foods such as soy milk, meat alternatives, and yeast spreads. The good news is that plant foods are widely fortified with B12 in the U.S. and Canada. Mushrooms, fermented soy products, and sea vegetables are unreliable sources, as they contain low or inactive forms for the human body.
  • Supplements: The human body needs at least 2.4 micrograms of vitamin B12 per day, and even more for women who are pregnant or breastfeeding. Research shows that it’s more effective to use a supplement with a lower dose (5–10 micrograms) every day rather than taking a high dose weekly.
  • Injections may be required for people whose doctor has confirmed that they cannot absorb vitamin B12. Also, it’s a good idea for those who are over 50, who are taking metformin, or who are vegan (or vegetarians who consume little or no dairy) to check their blood levels of B12 annually.

Nutritionist Sue Radd is the award-winning author of The Breakfast Book and coauthor of Eat To Live, internationally acclaimed for showing how savvy eating can combat cancer and heart disease and improve wellbeing. See for more nutrition information.

Food Matters: Getting Enough Vitamin B12

by Sue Radd
From the October 2012 Signs