Langan RC, Goodbred AJ. Vitamin B12 Deficiency: Recognition and Management. Am Fam Physician 2017;96:384-389.

However, one study suggests that doses up to 6 mcg of vitamin B12 per day may be appropriate for vegans ( 19). B12 for improved energy The rate is closer to 20% in people older than 60 years, though. Hence, vitamin B12 deficiency is pretty common in seniors. Vitamin B12 type: While it has been proposed that methylcobalamin, the active form of vitamin B12, is more readily absorbed than synthetic forms, research has not shown a significant difference. In particular, its Garden of Life Vitamin Code Raw B12 is a great option for people who prefer natural ingredients. It contains vitamin B12 derived from cultures of Saccharomyces cerevisiae, a yeast that is naturally occurring in some foods and is also known as brewer’s or baker’s yeast.

Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals

The average vitamin B12 level in the breast milk of women with vitamin B12 intakes above the RDA is 0.44 mcg/L [ 14]. The U.S. Food and Drug Administration (FDA) specifies that infant formulas sold in the United States must provide at least 0.15 mcg vitamin B12 per 100 kcal [ 15].No matter which testing option you use, the next step is to review the results with your healthcare provider. Vitamin B12, in the forms of cyanocobalamin and hydroxycobalamin, can be administered parenterally as a prescription medication, usually by intramuscular injection [ 2]. Parenteral administration is typically used to treat vitamin B12 deficiency caused by pernicious anemia as well as other conditions (e.g., tropical sprue, pancreatic insufficiency) that result in vitamin B12 malabsorption and severe vitamin B12 deficiency [ 5]. Most people in the United States consume adequate amounts of vitamin B12. Data from the 2013–2016 National Health and Nutrition Examination Survey (NHANES) show that only 3% of U.S. men had intakes from food and beverages below the EAR for vitamin B12 of 2 mcg, and the rate for women was 8% [ 30]. Vitamin B12 is a water-soluble vitamin that is naturally found in animal products. Some fortified foods, dietary supplements, and medications contain a synthetic version of vitamin B12. When you eat meat, fish, eggs, or dairy products, vitamin B12 is released from protein by hydrochloric acid and enzymes in the stomach; synthetic vitamin B12 is already in this released (free) form. Free vitamin B12 then combines with intrinsic factor — a substance secreted by the stomach cells—which enables it to be absorbed from the small intestine. Who needs more B12? If you are taking supplements that you have bought, follow the dosage instructions that come with them. How to take it

Your dose needs may change if you become pregnant, if you breastfeed, or if you eat a vegetarian diet. Tell your doctor about any changes in your diet or medical condition. Actually, there hasn’t been established a maximum safe dose for vitamin B12, as vitamin B12 has low toxicity. Too much vitamin B12 is unlikely to cause side effects in healthy people. Neither from food nor supplements. Conditions associated with vitamin B12 inadequacy include pernicious anemia, present in about 15% to 25% of older adults with vitamin B12 deficiency [ 43]. Atrophic gastritis, an autoimmune condition affecting 2% of the general population but 8%–9% of adults age 65 and older, decreases production of intrinsic factor and secretion of hydrochloric acid in the stomach and thus decreases absorption of vitamin B12 [ 43, 44]. A third condition associated with vitamin B12 deficiency in older adults is Helicobacter pylori infection, possibly because this bacterium causes inflammation that leads to malabsorption of vitamin B12 from food [ 45]. Individuals with pernicious anemia low potassium level - leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling. If your healthcare provider suspects a vitamin B12 deficiency, they’ll likely suggest a blood test to examine:Vitamin B12 is available in multivitamin/mineral supplements, in supplements containing other B-complex vitamins, and in supplements containing only vitamin B12. Multivitamin/mineral supplements typically contain vitamin B12 at doses ranging from 5 to 25 mcg [ 22]. Vitamin B12 levels are higher, generally 50–500 mcg, in supplements containing vitamin B12 with other B-complex vitamins and even higher, typically 500–1,000 mcg, in supplements containing only vitamin B12. Vitamin B12 injection – For some patients, the root cause of their B12 deficiency is their body’s difficulty in absorbing and retaining the B12 they consume through food. Injections bypass barriers to absorption. Patients who receive this treatment may receive just one injection or multiple shots over time. Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA