If you plan or prepare meals for vegetarians, have them as patients, are thinking about becoming a vegan, have been one for more than a year, desire to eat healthy, have a compromised immune system, take antacids regularly, have had gastric bypass surgery, are pregnant or trying to conceive a child, have numbness or tingling in extremities, or are near 50 years of age, continue reading this comprehensive article to prevent serious illness and expensive medical bills.
Regardless of food choices, our goal is to stay healthy, right? Vitamin B12, also known as methylcobalamin or cyanocobalamin, is an indispensable nutrient commonly found in a variety of non-plant based foods, such as fish, shellfish, meat, eggs, and dairy products. Because animal products provide optimum food sources for vitamin B12, vegans have the greatest risk for deficiency. Vegetarians who eat eggs and milk products are also at risk because, on average, they consume less than half of the adult Recommended Dietary Allowance (RDA) of vitamin B12. [1,2]
Symptoms of Vitamin B12 Malnutrition
Our bodies send out unpleasant signals when they crave essential nutrients. Early vitamin B12 cravings include decreased energy: weakness, fatigue, light-headedness, rapid heartbeat (tachycardia), panting; dermatological and dental indictions: pallor, easy bruising, sore tongue, bleeding gums; gastric disturbance: upset stomach, weight loss, diarrhea or constipation. Vitamin B12 deficiency can ultimately lead to several neurological and cardiovascular problems, including paresthesia (numb or painful extremities), cold hands and feet, depression, dementia  and cardiac distress.
Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis.
A normally functioning liver stores an adequate reserve of vitamin B12 for several years. Vegans are advised to have their B12 level checked every two years via methylmalonic acid (MAA) urine testing due to the unreliability of blood tests. Algae and other plant foods contain B12-analogues (false B12) that can imitate true B12 in blood tests while actually interfering with B12 metabolism. Values below approximately 170–250 pg/mL (120–180 picomoles/L) for adults indicate a vitamin B12 deficiency. [3,4]
Not Just Vegans At Risk
Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis. Vitamin B12 deficiency can have a number of possible causes. Typically it occurs in people whose digestive systems do not adequately absorb the vitamin from the foods they eat. [2,3] This can result from:
- Pernicious anemia, a condition in which there is a lack of a protein called intrinsic factor. The protein, which is made in the stomach, is necessary for vitamin B12 absorption.
- Atrophic gastritis, a thinning of the stomach lining that affects up to 30% of people aged 50 and older.
- Surgery in which part of the stomach and/or small intestine is removed.
- Small intestine conditions, such as Crohn’s disease, celiac disease, bacterial growth, or a parasite.
- Excessive alcohol excess consumption.
- Immune disorders, such as Graves’ disease, systemic lupus erythematosus or HIV.
- Antacid abuse.
Our bodies don’t produce vitamin B12. The RDA is 4 to 7 mcg per day for most adults. More is advised to actually absorb this amount. (NutritionFacts.org) A developing infant depletes its mother’s supply. Most women take folic acid in a prenatal vitamin during pregnancy. While folic acid is important for preventing birth defects, it can also “mask” some of the signs of a vitamin B12 malnutrition, making a deficiency much more difficult to detect. For proper care, expectant mothers should inform their Ob/Gyn if they are vegans.
Optimum Food Sources For B12
The easiest way for the average person to maintain adequate levels of vitamin B12 is to ingest it within foods. A full day’s supply of vitamin B12 can be obtained by eating 1 egg with a bowl of fortified cereal, 1 chicken breast, and 1 cup of plain yogurt. As the following table reveals, people restricted to plant-based diets are primarily limited to fortified foods (and perhaps tempeh and raw seaweeds with a caveat). **
|Clams, cooked||3 ounces||84.1||1,402|
|Liver, beef, cooked||3 ounces||70.7||1,178|
|Nori Seaweed, raw ** ||3 ounces||46.8||780|
|Kombu Seaweed, raw ** ||3 ounces||23.0||383|
|Breakfast cereals, fortified with 100% of the DV for vitamin B12||1 serving||6.0||100|
|Trout, rainbow, wild, cooked||3 ounces||5.4||90|
|Salmon, sockeye, cooked||3 ounces||4.8||80|
|Temepeh ** ||3 ounces||4.3||71|
|Trout, rainbow, farmed, cooked||3 ounces||3.5||58|
|Tuna fish, light, canned in water||3 ounces||2.5||42|
|Cheeseburger, double patty and bun||1 sandwich||2.1||35|
|Haddock, cooked||3 ounces||1.8||30|
|Breakfast cereals, fortified with 25% of the DV for vitamin B12||1 serving||1.5||25|
|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|
|Cheese, Swiss||1 ounce||0.9||15|
|Beef taco||1 soft taco||0.9||15|
|Ham, cured, roasted||3 ounces||0.6||10|
|Egg, whole, hard boiled||1 large||0.6||10|
|Chicken, breast meat, roasted||3 ounces||0.3||5|
Vitamin B12 Supplements
A macrobiotic diet typically consists of 50–60% whole cereal grains, 5% soups, 20–25% vegetables, and 5–10% beans and sea vegetables. Occasionally, small quantities of other foods, such as seafood, may be included. Meat is avoided and little or no dairy or eggs are eaten. Vitamin supplements generally are not taken. 
Trace amounts of vitamin B12 can be found within tempeh, seaweeds and organic plants in specific geographic regions.** But unless and until these foods are shown consistently to correct vitamin B12 deficiency, vegans should not rely on them as a vitamin B12 source. 
Sadly, many raw vegans think they are ingesting plant-based vitamin B12 but in reality they aren't. Spirulina is not considered to be a reliable source of vitamin B12. Spirulina is a microalga supplement that predominantly contains pseudovitamin B12, which is biologically inactive in humans. Therefore, it is not possible to get sufficient amounts of vitamin B12 by eating unwashed organic produce, seaweeds or mushrooms grown in B12-rich soil. [7,8] Vitamin B12 can be produced industrially only through bacterial fermination-synthesis for supplements and fortification.
To prevent malnourishment, Dr. Andrew Weil recommends taking 50 mcg as part of a B-Complex that contains a full spectrum of B vitamins, including biotin, thiamine, B12, riboflavin and niacin. [9,14] If for any reason you choose to avoid fortified foods or supplements, recognize that you are carrying out a dangerous experiment that many have tried before with consistently low levels of success. 
To get the full benefit on a vegan diet, do one of the following:
- Eat fortified foods 2 or 3 times a day to get at least 3 mcg B12 a day.
- Take one sublingual B12 supplement daily providing at least 10 mcg.
- Take a weekly sublingual B12 supplement providing at least 2000 mcg.
- Take supplement prescribed by personal physician.
Apart from other B vitamins, B12 tablets should be slowly dissolved beneath the tongue. This is comparable to B12 injections. Oral and sublingual tablets are available.
Take care that excess heating or pre-washing water-soluble vitamins, like B12, may destroy their potency. Most water-soluble vitamins breakdown quickly and are absorbed into the bloodstream. Generally, they cannot be amassed in our body and thus need to be consumed everyday. Instead of filtering and excreting the excess like other water-soluble vitamins, your body stores some B12 in your liver. Outside of darkened urine, which may mask other genitourinary problems, there are usually no other symptoms of overconsumption, though vitamin B12 is contraindicated with surgical stents, some medicines, and pre-existing medical conditions.
Vegetarian B12 Requirements
This is no treatise against veganism. Being informed may determine whether any of us decides to include animal products (like eggs, cheese or yogurt) in our diet or not. Consider the information presented as important guidelines to becoming a successful vegan, vegetarian, pescatarian or flexitarian, if you will. 
We should not assume that because we are eating mostly vegetables we must be healthy. Whether motivated by concern for animals, environmental impact, excessive antibiotics in the meat supply or a desire to minimize fats and lose weight, a vegetarian or vegan diet requires planing.  Along with a variety of the best fresh fruits and vegetables, we must include essential protein, omega-3, calcium, vitamin D and vitamin B12 as part of our regular nutrition.
Persons over 50 are advised to take a B12 supplement even if they consume animal products. Vitamin B12 deficiency symptoms intersect cardiovascular, endocrinological, dermatological, urology, gastroenterological, rheumatological, neurological, and obstetrics specialties. If you have health issues, it is wise to consult with a qualified physician before pursuing alternative health remedies. B12 levels are measured with a blood test.
- Normal range for vitamin B12 in the blood is between 200 and 900 nanograms per milliliter (ng/mL). Follow-up testing may be required based upon symptoms.
- Low levels of vitamin B12 are below 200 ng/mL. This suggests a vitamin B12 deficiency, pernicious anemia, or an overactive thyroid. People with low vitamin B12 levels often experience neurological symptoms.
- High vitamin B12 level is anything over 900 ng/mL. This may suggest liver or kidney problems, diabetes, or certain forms of leukemia.
Are you craving vitamin B12? You should be, whether you are symptomatic or not. It’s an essential vitamin affecting our energy, skin, digestion, heart function, genetic reproduction and thought processes. Which source will you choose? Nutritional guidelines are available for vegans/
Vitamin B12 Overview
Everything you want to know about vitamin B12 but were afraid to ask: 
Vitamin B12 is required for the proper function and development of the brain, nerves, blood cells and many other parts of the body.
Vitamin B12 is useful in treating and preventing vitamin B12 deficiency, a condition in which B12 levels in the blood are too low. It is also used to treat pernicious anemia, a serious type of anemia that is due to vitamin B12 deficiency and is found mostly in older people. For this purpose, people use either a supplement that is taken by mouth (sublingually) or a gel that is applied inside the nose.
Vitamin B12 is also used for memory loss, Alzheimer’s disease, boosting mood, energy, concentration and the immune system, and slowing aging. It is prescribed for heart disease, lowering high homocysteine levels (which may contribute to cardiovascular disease), male infertility, diabetes, sleep disorders, depression, mental disorders, weak bones (osteoporosis), swollen tendons, AIDS, inflammatory bowel disease, asthma, allergies, a skin disease called vitiligo, preventing cervical and other cancers, and skin infections.
Some people receive vitamin B12 for amyotrophic lateral sclerosis (Lou Gehrig’s disease), multiple sclerosis, preventing the eye disease age-related macular degeneration (AMD), Lyme disease and gum disease. It is also used for ringing in the ears, bleeding, liverand kidney disease, and for protection against the poisons and allergens in tobacco smoke.
As a dermatological treatment for psoriasis and eczema, vitamin B12 is applied to skin either alone or in combination with avocado oil. Vitamin B12 is frequently used in combination with other B vitamins in vitamin B-complex products.
B12 Injections For Weight Loss?
Some weight-loss clinics offer vitamin B12 injections. Proponents of the injections say the shots provide more energy and boost metabolism, helping to shed unwanted pounds. But unless there is a vitamin B12 deficiency, such injections are not likely to offer any energy boost.
Getting large amounts of vitamin B12 through injections isn’t likely to harm your health. Arguably, it is no better than sublingual tablets or drops. Vitamin B12 can interfere with the effectiveness of some medications or stents, so if you receive vitamin B12 injections, be sure to let your doctor know. 
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- Vitamin B12 Background. mayoclinic.com
- Vitamin B12 Deficiency. webmd.com
- Vitamin B12 Dietary Supplement Fact Sheet. nih.gov
- USDA National Nutrient Database. usda.gov
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- B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods. veganhealth.org
- Recommended Supplements for Vegans. theveganrd.com
- Vitamin B12 sources and bioavailability. Watanabe F. Exp Biol Med (Maywood). 2007 Nov; 232(10):1266-74. nih.gov
- Facts About Vitamin B12. drweil.com
- What Every Vegan Should Know About Vitamin B12. vegansociety.com
- Not All Vegetarians Are The Same. ClinicalPosters.com
- Vegetarian diet: How to get the best nutrition. mayoclinic.com
- Tips for Vegetarians. choosemyplate.gov
- Vitamin B12 Overview. webmd.com
- Are vitamin B12 injections helpful for weight loss? mayoclinic.com
Access more article features and references.