Are you feeling fatigued? Has your vitamin B12 level been tested? Vitamin B12 is required for making DNA, healthy red blood cells, nerves, and metabolism in humans. A low level of vitamin B12 can cause “macrocytic anemia”. This means that there are not enough healthy red blood cells to deliver oxygen to the body’s tissues. Without enough oxygen, people feel tired. Vitamin B12 deficiency can also cause nerve-related symptoms, for example: prickling or tingling of the legs or arms, loss of vibration sensation, loss of balance, and even memory-related problems.
Who is at risk for vitamin B12 deficiency?
- Vegans & vegetarians. Vitamin B12 is only found in meat and dairy products.
- People with digestive issues. Vitamin B12 is difficult to absorb, so any malabsorption can cause deficiency. Risk factors include gastric bypass surgery, irritable bowel disease, etc.
- Some medications. Commonly prescribed medications such as protein pump inhibitors (for stomach acid) and metformin (for diabetes) may block the absorption of vitamin B12.
- Those with chronic illness. Chronic diseases are a long term stressor on the body and increase the requirement for vitamin B12.
How much vitamin B12 do you need?
The minimum requirement for vitamin B12 is 2.4 mcg/day in healthy adults. The requirement is increased for pregnant or breastfeeding women (2.6 and 2.8 mcg/day respectively). Children need a little less vitamin B12, ranging from 0.4mcg to 2.4mcg depending on age.
Food Sources of Vitamin B12
Vitamin B12 is only found in meat & dairy products (plus some fortified foods). Liver and some seafood are the highest in vitamin B12. However, vitamin B12 is easiest to absorb from cow’s milk and fish. Including any vitamin B12 source in your diet should be sufficient. Keep in mind that the body can only absorb a little vitamin B12 at a time. Generally, the body can only absorb 1-2mcg of vitamin B12 from food per meal. See the table below for vitamin B12 content of foods:
| Over 2.4 mcg per 75g serving | All organ meats: kidney, liver, turkey giblets etc. Ground beef Caribou or reindeer Clams, oysters, mussels, mackerel, herring, tuna, crab, canned sardines, caviar, trout, red/sockeye salmon, canned salmon |
| 1.2 – 2.4 mcg per serving (75g unless specified otherwise) | Milk (1 cup), swiss cheese (50 g) Various cuts of beef Wild atlantic salmon, canned tuna Soy-based meat substitutes, egg (2 large) |
| <1.2 mcg vitamin B12 | Buttermilk (1 cup), cottage cheese (1 cup), most cheeses (50g), greek yogurt Pork products, turkey, duck or chicken Soy, almond, oat, or rice beverages (1 cup) |
Do you have any questions about vitamin B12? Have you seen your naturopathic or medical doctor for bloodwork recently?
References:
Nathan and Oski’s Hematology and Oncology of Infancy and Childhood: Cobalamin (Vitamin B12) Carmel, Ralph; Watkins, David; Rosenblatt, David S… Published January 1, 2015. © 2015.
Medscape. (2019). A Diagnosis to Consider: Vitamin B12 Deficiency. [online] Available at: https://www.medscape.com/viewarticle/730237 [Accessed 21 Aug. 2019].
