Unlocking the secrets of optimal health often leads us to explore the intricate world of vitamins, and among them, vitamin B12 takes center stage. With its pivotal role in functions ranging from nerve health to red blood cell formation, vitamin B12 is an essential nutrient that our bodies depend on. However, unlike some vitamins, our bodies can't manufacture B12 on their own.
This article serves as a comprehensive guide, delving into the diverse sources that provide us with this vital nutrient and examining the potential risks and consequences associated with vitamin B12 deficiency. If you want a quick briefing about B12, you can read 'Introduction to Vitamin B12'.in B12 Vitamin B12Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B1 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12 Vitamin B12
Join Weekly Health Newsletter
Every week, I will share with you information about Natural Health, Diet, Exercise, Yoga & Wellness.
SOURCES OF VITAMIN B12
Food | Micrograms per Serving | Percentage DV |
|---|---|---|
Cooked Clams (without shells), 85gm | 17 | 708 |
Fortified nutritional yeast, 1/4 cup | 8.3 - 24 | 346 - 1000 |
Cooked Atlantic Salmon, 85gm | 2.6 | 108 |
Light Tuna (canned in water), 85gm | 2.5 | 104 |
Milk with 2% Milkfat, 1 cup | 1.3 | 54 |
Plain Fat-free Yoghurt, 170gm | 1 | 43 |
Fortified Breakfast Cereal, 1 serving | 0.6 | 25* |
Cheddar Cheese, 42.5gm | 0.5 | 19 |
Whole Cooked Egg, 1 large | 0.5 | 19 |
Roasted Turkey Breast, 85gm | 0.3 | 14 |
Tempeh, 1/2 cup | 0.1 | 3 |
Banana, 1 medium | 0 | 0 |
Kidney Beans, 1/2 cup | 0 | 0 |
The U.S. Food and Drug Administration (FDA) devised Daily Values (DVs) to facilitate informed comparisons of nutrient compositions among foods and dietary supplements in the broader context of dietary intake.
In the case of vitamin B12, the recommended Daily Value stands at 2.4 mcg for both adult individuals and children aged 4 years and older. Foods that furnish 20% or more of this DV are categorized as high sources of the nutrient. However, it is important to note that even foods delivering lower percentages of the DV play a meaningful role in cultivating a health-conscious diet.
The U.S. Department of Agriculture's FoodData Central is catalogues the nutrient profiles of diverse foods. This resource presents a comprehensive list of vitamin B12-rich foods, organized based on their nutrient content and food name. The accompanying table showcases some of the major sources of vitamin B12 within this compilation.
Analyzing the table, it is apparent that most of the sources are of animal-origin; meat, egg, milk, yoghurt, cheese, fish. This acts as an evidence to the fact that vegetarians and vegans are more prone to deficiency of vitamin B12.
Some other sources that one can take are dietary supplements and prescription medications. The most common form of supplement is cyanocobalamin. It is also taken in the form of adenosylcobalamin, methylcobalamin, and hydroxycobalamin.
DEFICIENCY OF VITAMIN B12
Vitamin B12 deficiency, medically referred to as cobalamin deficiency, occurs when the levels of vitamin B12 in the
blood and tissues are below the normal range.
But relying solely on blood tests to gauge deficiency isn't the most accurate method, as certain individuals with a deficiency might exhibit regular vitamin B12 blood levels. More reliable indicators of actual vitamin B12 activity are the blood concentrations of methylmalonic acid, a byproduct of protein breakdown, and homocysteine. These values rise in the presence of a vitamin B12 deficiency.
CAUSES OF DEFICIENCY:
Vitamin B12 deficiency primarily has 3 etiologies : Dietary Insufficiency, Malabsorption, and Autoimmune.
Autoimmune Cause
Pernicious anemia is a relatively rare autoimmune condition that hampers the absorption of dietary vitamin B12, leading to a deficiency of B12 and then megaloblastic anemia. In this disorder, antibodies against intrinsic factor, a protein necessary for B12 absorption, are generated.
These anti-intrinsic factor antibodies attach themselves to intrinsic factor, impeding its functionality, which in turn renders the terminal ileum incapable of absorbing B12.
Dietary Insufficiency
Vitamin B12 accumulates in surplus within the liver; nevertheless, individuals who have strictly adhered to a vegan diet for roughly three years might encounter a B12 deficiency due to insufficient dietary intake.
Individuals who exclude meat, fish, poultry, and dairy from their diets face the possibility of lacking in vitamin B12, as it is exclusively present in animal-derived products. Research has indicated that individuals following a vegetarian lifestyle tend to exhibit diminished levels of vitamin B12 in their bloodstreams.
Therefore, individuals practicing a vegetarian or vegan dietary regimen should incorporate B12-fortified foods or take B12 supplements. This is of particular significance for pregnant women, as proper vitamin B12 is crucial for fetal neurological development, and deficiency can result in permanent neurological impairment.
Malabsorption
There are various reasons for malabsorption, ranging from medication to physical inability to absorb.
SURGERY :
Parietal cells are a specialized form of gastric cells (in stomach) that secrete Intrinsic Factor and ileum (small intestine) is the site of absorption of B12. So, any surgery related to these locations may lead to the deficiency of B12. For example, a patient with a history of gastric bypass
surgery (weight loss surgery) may develop the deficiency. Also, a surgical resection of terminal ileum (due to Crohn's disease) may increase the risk of deficiency. To know more about Crohn's disease and its holistic treatment, you may visit Ayurvedic Herbalist.
GASTROINTESTINAL DISORDERS :
Certain diseases including Crohn’s and celiac disease that negatively impact the digestive tract also increase the risk of deficiency. Other than that, gastritis (inflammation of stomach lining) is a common cause of B12 deficiency. This occurs due to a lack of hydrochloric acid, which is a key component for absorption. You can understand more about the way B12 is absorbed in 'Introduction to Vitamin B12'.
MEDICATIONS:
The extended usage of metformin, a commonly prescribed drug for type 2 diabetes, is strongly linked to deficiencies in vitamin B12 and lower levels of folic acid. This is primarily because metformin can hinder the absorption of these essential nutrients, potentially resulting in elevated levels of homocysteine and an increased risk of cardiovascular disease. Similarly, individuals taking proton pump inhibitors and histamine blockers, medications aimed at reducing stomach acid, are also at risk of experiencing reduced vitamin B12 levels.
Individuals who frequently rely on medications that suppress stomach acid due to conditions like gastroesophageal reflux disease (GERD) or peptic ulcer disease—such as proton-pump inhibitors, H2 blockers, or other antacids—may encounter difficulties in absorbing sufficient vitamin B12 from their diets.
These medications can slow down the release of stomach acid or reduce its production, which could potentially impede the conversion of vitamin B12 into a usable form in the stomach. Nevertheless, current research has not provided evidence for a significantly higher incidence of vitamin B12 deficiency in people using these medications.
HIGH RISK POPULATIONS:
- AGE OVER 75 : Individuals above the age of 75 are more susceptible to developing vitamin B12 deficiency due to potential difficulties in fully absorbing the vitamin by their bodies.
- GI DISORDER : Conditions like celiac disease and Crohn’s disease can complicate the absorption of vitamin B12 in the body.
- STRICT VEGAN OR VEGETARIAN DIET : Those who follow this diet are at an increased risk of vitamin B12 deficiency if their diet lacks sufficient fortified foods containing the vitamin.
- TAKING SPECIFIC MEDICATIONS : Certain medications can lead to decreased levels of vitamin B12 in the body. These include metformin (a medication used to manage diabetes), proton pump inhibitors (PPIs used to treat GERD and peptic ulcers), histamine H2 blockers (used to reduce stomach acid production), and oral birth control pills (oral contraceptives).
SYMPTOMS:
The outlook (prognosis) for individuals with vitamin B12 deficiency relies on the promptness of diagnosis and treatment. When the deficiency is identified early, most individuals can alleviate their symptoms through treatment. The duration of medication needed varies depending on the underlying cause of the deficiency; it could be a short-term regimen or require lifelong medication.
GENERAL :
- Feeling very tired or weak.
- Experiencing nausea, vomiting or diarrhea.
- Not feeling as hungry as usual.
- Weight loss.
- Having a sore mouth or tongue.
- Having yellowish skin.
NEUROLOGICAL :
- Numbness or tingling in your hands and feet.
- Vision loss.
- Having a hard time remembering things or getting confused easily.
- Having a difficult time walking or speaking like you usually do.
PHYSIOLOGICAL :
- Feeling depressed, irritable and
- Experiencing a change in the way you feel and behave.
Neglecting to address vitamin B12 deficiency can lead to enduring and significant consequences that impact the nervous system and brain. Some of the more severe and lasting effects of untreated vitamin B12 deficiency are :
- Megaloblastic Anemia: It is characterized by red blood cells that are larger than normal. As the red blood cells are too large, they may not be able to exit the bone marrow to enter the bloodstream and deliver oxygen.
- Nerve damage with numbness, tingling in the hands and legs
- Depression
- Paranoia and delusions
- Memory loss
PREVENTION OF B12 DEFICIENCY
Preventing vitamin B12 deficiency involves ensuring an adequate intake of this essential nutrient through various dietary and supplemental means. It is achievable for most individuals through the consumption of foods and beverages containing vitamin B12. Here are some foods you can add to your diet :
ANIMAL-DERIVED FOODS : Vitamin B12 is present in red meat, fish, poultry, eggs, as well as milk and other dairy products.
FORTIFIED FOOD : Fortified foods are enriched with vitamins and nutrients they naturally lack. Examples include select breakfast cereals, nutritional yeast, plant-based milk, and specific types of bread. Ensure you review the food label (nutritional information) to determine if the item has been fortified with vitamin B12.
VITAMIN B12 SUPPLEMENTS : Numerous multivitamins contain vitamin B12, and standalone supplements focused solely on vitamin B12 are also available. This is one of the few options available to vegans and vegetarians, apart from fortified foods.
REFERENCES
Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B(6), Folate, Vitamin B(12), Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academies Press; 1998. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK114310/
Vitamin B12-Fact Sheet for Medical Professionals. National Institutes of Health (NHI). Retrieved from https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/#en1
Vitamin B12 Deficiency. Diseases and Conditions, Health Library, Cleveland Clinic. Retrieved from https://my.clevelandclinic.org/health/diseases/22831-vitamin-b12-deficiency
Vitamin B12. The Nutrition Source, Harvard T.H. Chan. Retrieved from https://www.hsph.harvard.edu/nutritionsource/vitamin-b12/
Vitamin B-12. By Mayo Clinic Staff. Retrieved from https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663
Ankar A, Kumar A. Vitamin B12 Deficiency. [Updated 2022 Oct 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441923/
Join Weekly Health Newsletter
Every week, I will share with you information about Natural Health, Diet, Exercise, Yoga & Wellness.
0 comments