Vitamin B12 is a water soluble vitamin that serves as an aid to the nervous system and plays a vital role in red blood cell formation and DNA synthesis. Ultimately it is responsible for normal neurological functions and beneficial for overall health.
Vitamin B12 is considered a unique vitamin based off of its structure and absorption into the body. It’s structure is unique because it’s the only vitamin that contains a metal- cobalt part. This is why cobalamin is the term used to express B12 activity. The most common type of cobalamin is found in most dietary supplements of B12, cyanocobalamin, and is quickly transformed into an active form of B12 in the body (8).
The other unique trait to vitamin B12 is its multi-step process needed for absorption into the body. B12 is found in animal protein. After consuming the animal protein with B12 bound to it, it heads down towards the stomach where hydrochloric acid is needed to release B12 from the protein. Once B12 is released, it attaches itself to a substance called intrinsic factor, which is secreted by the cells inside the stomach. From there, the B12-intrinsic factor can be absorbed into the intestinal tract with the aid of calcium (8).
B12 deficiencies can be caused by impaired absorption or a decrease in intake. Vitamin B12 is found in natural animal products which include fish, meat, poultry, eggs and dairy products. Resultantly, those with a strict vegetarian diet are at a greater risk for vitamin B12 deficiency as it is not typically found in plant-based food sources. Examples of food sources with vitamin B12 are listed below (7):
| Food Source | Micrograms (mcg) per serving: | Percent Daily Value (DV): |
|---|---|---|
| Clams, cooked, 3 ounces | 84.1 | 1,402 |
| Beef, top sirloin, broiled, 3 ounces | 1.4 | 23 |
| Milk, low-fat, 1 cup | 1.2 | 18 |
| Yogurt, fruit, low-fat, 8 ounces | 1.1 | 18 |
| Egg, whole, hard boiled, 1 large | 0.6 | 10 |
| Salmon, sockeye, cooked, 3 ounces | 4.8 | 80 |
| Liver, beef, cooked, 3 ounces | 70.7 | 1,178 |
Due to its importance with regard to the central nervous system, B12 has a crucial role in the health of the myelin sheath, a connective tissue that wraps each nerve fiber. Low B12 counts may cause the myelin sheath to swell and disintegrate, leading to brain abnormalities and spinal cord degeneration (1). It also has the potential to cause pernicious anemia; which allows for the formation of larger than normal red blood cells. When compared to smaller red blood cells, larger cells may have difficulty leaving the bone marrow where they are produced. If there is a reduction in red blood cells in the circulatory system, oxygen levels are decreased throughout the rest of the body. As a result, damage may occur in the brain, heart, and other vital organs of the body if left untreated for prolonged periods of time (4). Some examples of Vitamin B12 deficiencies are listed in the chart below (7):
| Fatigue | Numbness | Tingling in Hands & Feet | Shortness of Breath | Depression |
| Pale Skin | Loss of appetite | Muscle weakness | Sore tongue and mouth | Rapid Heart Beat |
| Memory loss | Brain fog | Issues with Balance | Weakness | Dementia |
Blood testing may be ordered to determine a deficiency of B12. A Complete Blood Count (CBC) is normally the first blood test ordered to investigate the underlying cause of vitamin deficiencies. Indications of anemia include a low red blood cell count and an elevated mean corpuscular volume (MCV). An elevated MCV indicates that the red blood cells are enlarged, thus leading to anemia. Additional blood testing can be ordered to rule out other possible causes of B12 deficiencies such as a comprehensive metabolic panel, antinuclear antibody (ANA), C-reactive protein (CRP), and/or Rheumatoid factor (RF).
A deficiency of B12 can be caused in one of two ways: malnutrition or malabsorption. Malnutrition is often seen in vegan diets without animal protein. Malabsorption occurs when vitamin B12 is having difficulty being absorbed in the small intestine and can be influenced by one of the following ailments or behaviors (3,4,5,6):
• Celiac disease
• Inflammatory bowel disease. This includes ulcerative colitis and Crohn’s disease.
• Bacterial overgrowth in the intestines
• Reduced stomach acid caused by the use of antacids.
• Excessive smoking and alcohol consumption
• Certain Diabetic (Metformin), Acid reflex (Omeprazole), Cancer (Methotrexate) medications.
• Surgeries that remove parts of the stomach or intestines.
There are multiple reasons why Vitamin B12 should be supplemented. Like the other B vitamins, it is water soluble. Any excess B12 is excreted in the urine instead of being stored in the body. B12 can be taken in through the diet, sublingual supplementation or injections.
Nutritional Blood Testing is the key to understanding vitamin B12 levels. In fact, if you are low in vitamin B12, chances are you are deficient in other nutrients as well. Finding out where your nutritional status lies and getting a good baseline is recommended at any age. Let us guide you down the right path with an individualize plan that is constructed specifically towards your needs and help you discover a safe and natural option to benefit your health.
References:
1. Fink, Heather Hedrick., Lisa A. Burgoon, and Alan E. Mikesky. “Chapter 6 Vitamins.” Practical Applications in Sports Nutrition. Sudbury, MA: Jones and Bartlett, 2006. 163-67. Print.
2. Insel, Paul M., Don Ross, Kimberley McMahon, and Melissa Bernstein. “Chapter 11 Water-Soluble Vitamins.” Nutrition. 6th ed. N.p.: n.p., n.d. 451. Print.
3. “Vitamin B12 (Cobalamin) Importance after Bariatric Surgery.” Vitamin B12 Importance after Bariatric Surgery. N.p., n.d. Web. 13 Aug. 2016.
4. “What Is Pernicious Anemia?” What Is Pernicious Anemia. National Heart, Lung and Blood Institute, 11 Apr. 2011. Web. 13 Aug. 2016.
5. Dharmarajan, TS, Norkus, EP (2001). Approaches to vitamin B12 deficiency: Early treatment may prevent devastating complications. Postgrad Med, 110(1): 99-105.
6. Guidelines and Protocol Advisory Committee (2003). Investigation and management of vitamin B12 and folate deficiencies. Medical Services Commission and B. C. Medical Association.
7. “Office of Dietary Supplements – Dietary Supplement Fact Sheet: Vitamin B12.” Dietary Supplement Fact Sheet: Vitamin B12 — Health Professional Fact Sheet. National Institutes of Health, n.d. Web. 21 Aug. 2016.
8. “Staying Healthy Newsletter Spotlight on Vitamin B12.” Staying Healthy Newsletter. Science Based Health, n.d. Web. 31 Aug. 2016
