Nutrient Information: Vitamin B12

Nutrient Key Information
Nutrient Name:	Vitamin B12
Nutrient Category:	Vitamins and Other Components
Unit Name:	µg
Nutrient Summary:	Vitamin B12 is essential for normal blood formation and neurological function.

Sample Foods High in: Vitamin B12 - All Food Categories - Dairy and Egg Products Vegetables and Vegetable Products Fruits and Fruit Juices Cereal Grains and Pasta Legumes and Legume Products Breakfast Cereals Beverages Poultry Products Beef Products Pork Products Finfish and Shellfish Products Lamb, Veal, and Game Products Sausages and Luncheon Meats Fats and Oils Baked Products Sweets Snacks Fast Foods Restaurant Foods American Indian/Alaska Native Foods Additional Top Food Sources
	Food Description	Nutrient Amount1	Daily Value%2
	Mollusks, clam, mixed species, cooked, moist heat Category: Finfish and Shellfish Products Similar foods: cooked clam	98.89 µg	4,120.42%
	Beef, variety meats and by-products, liver, cooked, pan-fried Category: Beef Products Similar foods: cooked beef liver	83.13 µg	3,463.75%
	Mollusks, oyster, Pacific, cooked, moist heat Category: Finfish and Shellfish Products Similar foods: oyster	28.8 µg	1,200.00%
	Fish, mackerel, Atlantic, cooked, dry heat Category: Finfish and Shellfish Products Similar foods: mackerel fish	19 µg	791.67%
	Fish, tuna, fresh, bluefin, cooked, dry heat Category: Finfish and Shellfish Products Similar foods: cooked tuna fish	10.88 µg	453.33%
	Crustaceans, crab, dungeness, cooked, moist heat Category: Finfish and Shellfish Products	10.38 µg	432.50%
	Beef, plate steak, boneless, outside skirt, separable lean and fat, trimmed to 0" fat, all grades, cooked, grilled Category: Beef Products Similar foods: cooked beef plate skirt	7.72 µg	321.67%

Nutrient Detail Information
Nutrient Summary	Vitamin B12 is essential for normal blood formation and neurological function.
Nutrient Function	• Red blood cell formation and prevent anemia • Nerve cells and nervous system function. It may play a role in preventing brain atrophy which often associated with memory loss or dementia. • Conversion of food into energy by metabolism of certain fatty acids and amino acids. • Help DNA synthesis Vitamin B12 is processed in the stomach and the small intestine, and then released into the circulation. To absorb vitamin B12 from foods, there are two steps (vitamin B12 absorption from supplements only needs step #2): 1) Hydrochloric acid in the stomach separates vitamin B12 from the protein that it's attached to. 2) The freed vitamin B12 combines with a protein made by the stomach, called intrinsic factor. Some people cannot absorb Vitamin B12 well: 1) People older than 50 years old who produce less hydrochloric acid in their stomach. 2) People with autoimmune diseases who cannot produce enough hydrochloric acid and/or intrinsic factor. 3) People with stomach or intestinal surgery who cannot produce enough hydrochloric acid and/or intrinsic factor. 4) People who eat little or no animal foods. 5) Vitamin B12 is water-soluble. Water-soluble vitamin moves directly into the blood, and not well stored in the body.
Food Sources Top Food Sources	Foods naturally containing vitamin B12 are primarily animal origin foods: • Shellfish, such as clams • Organ meats, such as beef liver • Fish, such as herring, sardines, tuna, trout, salmon • Dairy products, such as milk (cautious: boiling milk will significantly reduce the Vitamin B12 content) • Eggs • Meat • Poultry Attention for vegan diet (pure vegetarian): plant foods have no vitamin B12 unless they are fortified, such as fortified ready-to-eat cereals and meal replacement formulas. Note: 1. 10–30% of people older than 50 years old may be unable to absorb naturally occurring vitamin B12 because of the lower stomach acid secretion caused by the atrophic gastritis. Experts advise people older than 50 to consume foods fortified with vitamin B12 or take Vitamin B12 supplements to meet their daily Vitamin B12 needs.
Deficiency Health Effects	The common symptom of vitamin B12 deficiency is fatigue or lack of energy. The main problems with vitamin B12 deficiency are: • Hematological effects: megaloblastic anemia or pernicious anemia. Symptoms include weakness, fatigue, shortness of breath, and palpitations. When anemia is established, some degree of neutropenia and thrombocytopenia may occur. • Neurological effects: Neurological complications are present in 75–90% of individuals with vitamin B12 deficiency. Symptoms include tingling and numbness in the limbs, gait disturbances, loss of concentration, memory loss, disorientation, dementia, visual disturbances, insomnia, depression. • Gastrointestinal effects: Vitamin B12 deficiency is often associated with gastrointestinal complaints, such as loss of appetite, flatulence, and constipation. Note: Excessive folate intake from supplement may obscure the vitamin B12 deficiency that can result in unrecognized neurological damage.
Effects if Above Upper Limit	Due to inadequate data on adverse effects of excess vitamin B12 consumption, a Upper Limit for the vitamin B12 could not be determined. No adverse effects have been associated with excess vitamin B12 intake from food or supplements in healthy individuals. Apparently only a small percentage of vitamin B12 can be absorbed from the gastrointestinal tract.
External References	Learn more at: • The National Academies of Science, Engineering, Medicine publication: Dietary Reference Intakes • healthline.com Article: 9 Health Benefits of Vitamin B12, Based on Science • NIH (National Institutes of Health) Article: Vitamin B12

Daily Value Age Group	Recommended Daily Values
Toddler 1 to 3 years old:	0.9 µg
Child 4 to 8 years old:	1.2 µg
Male 9 to 13 years old:	1.8 µg
Male 14 to 18 years old:	2.4 µg
Male 19 to 30 years old:	2.4 µg
Male 31 to 50 years old:	2.4 µg
Male 51 to 70 years old:	2.4 µg
Male Senior 71 or older:	2.4 µg
Female 9 to 13 years old:	1.8 µg
Female 14 to 18 years old:	2.4 µg
Female 19 to 30 years old:	2.4 µg
Female 31 to 50 years old:	2.4 µg
Female 51 to 70 years old:	2.4 µg
Female Senior 71 or older:	2.4 µg
Female Pregnancy (>18):	2.6 µg
Female Lactation (>18):	2.8 µg
FDA (Based on 2000 calorie daily diet):	2.4 µg

	The nutrient Dietary Reference Intakes and nutrition facts is from Institute of Medicine of National Academies 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. https://doi.org/10.17226/11537
	Nutrition facts knowledge are based on U.S. FOOD & DRUG Administration Nutrition Education Resources & Materials. https://www.accessdata.fda.gov/scripts/interactivenutritionfactslabel/
	Nutrition facts knowledge are based on National Institutes of Health Dietary Supplement Fact Sheets. https://ods.od.nih.gov/factsheets/list-all
Disclaimer	The nutrient information provided here should not take the place of medical advice. We encourage you to talk to your healthcare providers (such as your doctor) about your dietary requirements which are best for your overall health. We also recommend you to read organization or professional reference documents or articles mentioned, but not limited to, in this page. Any mentions and reference links in this page don't represent our endorsement of their services and advice.