High Levels of B12 & Side Effects

If you are over the age of 14 and are not pregnant or breastfeeding, health professionals with MayoClinic.com recommend that you consume at least 2.4 micrograms of vitamin B-12 each day. This essential, water-soluble nutrient influences how your brain functions and also helps your body produce red blood cells and DNA.

No Side Effects

Vitamin B-12 is a water-soluble vitamin, which means that excess levels of this nutrient are excreted from the body in your urine rather than being stored in your tissues or organs. Consequently, if you ingest unusually high levels of vitamin B-12, you are unlikely to experience side effects, according to the Office of Dietary Supplements.

Food Sources of Vitamin B-12

Consuming meat products, such as beef, chicken or fish, can help ensure that your body receives enough vitamin B-12 to function normally. Three ounces of broiled top sirloin provides 2.4 micrograms of vitamin B-12, the ODS reports. Additional sources of vitamin B-12 include dairy products, such as yogurt, cheese and milk, and fortified breakfast cereals.

Symptoms of Low Vitamin B-12 Levels

Unusually low levels of vitamin B-12 may be the result of a medical condition called pernicious anemia. If you have this form of anemia, your body is unable to absorb sufficient levels of vitamin B-12 from the food products you ingest. When this occurs, your body is unable to produce enough red blood cells. Symptoms of pernicious anemia include:

  • fatigue
  • weakness
  • memory loss
  • digestive problems
  • the National Heart Lung Blood Institute warns [1](https://www.nhlbi.nih.gov/health-topics/pernicious-anemia 'inline-reference::National Heart Lung Blood Institute: Pernicious Anemia
  • Vitamin B-12 Deficiency')

Talk with your doctor if you develop symptoms of low vitamin B-12 levels. Your doctor may recommend treatment with an oral or injectable form of a vitamin B-12 supplement.