Vitamin B12 is an essential nutrient that must be ingested daily because our bodies don’t naturally produce it.
B12 is important for many enzymatic processes, such as helping turn the food you eat into usable energy.†
The recommended daily amount for B12 is 2.4 mcg for adults. Pregnant and lactating women need higher amounts .
There is no upper intake limit for vitamin B12 because there is no known toxicity .
Most vitamin B12 supplements provide a range of strengths between 500 to 5,000 mcg .
Taking a vitamin B12 supplement may help reduce fatigue for those with low vitamin B12†
Vitamin B can be classified into eight different nutrients, each with benefits for our overall health. Vitamin B12 (Cobalamin) is a water-soluble vitamin that our bodies don’t naturally produce enough of on their own and is therefore considered an “essential” nutrient. That means we need to ingest vitamin B12 from foods and/or supplements every day .
Where do we get vitamin B12? B12 is found in all animal products (meat, fish, eggs, dairy). Some non-animal-based foods are fortified with vitamin B12, such as breakfast cereals, non-dairy milk, and nutritional yeast .
Because vitamin B12 is vital for nervous system function and helps support red blood cell formation and cellular energy production, it is important to ensure that you’re getting adequate B12 from your diet. In this article, we’ll discuss how much vitamin B12 you should ingest daily, whether from your diet or the addition of supplements.†
How Much Vitamin B12 Should I Take Daily?
The Food and Nutrition Board sets the recommended daily allowance (RDA) for most nutrients, whether a vitamin or mineral. The board also sets tolerable upper intake levels (UL) for these nutrients, which is the maximum amount that can be consumed daily without likely side effects. For vitamin B12, there is no set UL since there are currently no known side effects when consuming more than the RDA .
So then how much vitamin B12 should one ingest (or eat) in a day? As we age, our ability to absorb nutrients from foods and supplements decreases, which means adults, especially those over age 50, might benefit from higher amounts of vitamin B12. In addition, vitamin B12 supplements usually range from 500 mcg to 5,000 mcg per serving to provide you with a variety of strengths and allow you to customize to meet your needs . Even though the RDA for vitamin B12 is 2.4 mcg for adults, you may take higher amounts since your body will only absorb what it needs and then excrete the rest .
Like vitamin D, daily intake of vitamin B12 is important to ensure you are supplying your body with the nutrients it needs to function.If you are taking a multivitamin or a B Complex vitamin, be sure to check the amount of vitamin B12 provided per serving so that you know how much B12 you are taking every day through your supplement to meet your daily nutrient needs, but also consider how much vitamin B12 you are getting from the foods you eat each day.
What Are the Suggested Amounts for Vitamin B12 By Age?
Glad you asked. The recommended daily allowance for vitamin B12 varies by age. Check out the chart below to see how much you should consume daily, either through your diet or through supplements if your diet does not regularly include animal products or foods fortified with B12 :
Is It Okay to Take 5,000 mcg of Vitamin B12 a Day?
Taking a vitamin B12 supplement may help you meet adequate levels of B12 in your body. As stated earlier, there is no set upper limit for vitamin B12 . If you ingest more of this nutrient than your body requires, the excess amount should be excreted in your urine. A maximum strength vitamin B12 supplement can provide 5,000 mcg of B12 per serving and is designed for adults with very low levels of vitamin B12 as determined by a healthcare professional.†
For those adults who have a diagnosed vitamin B12 deficiency∆, or for those who are not able to easily absorb vitamin B12 from food or a B12 supplement, prescriptions are available, such as vitamin B12 injections directly into the muscle . If you are concerned you might have a B12 deficiency, especially if you keep a vegan or vegetarian diet or are over age 50, make an appointment with a healthcare professional to check your levels to determine if you have a vitamin B12 deficiency and if so, the adequate vitamin B12 dosage for your needs.
In addition, certain medications may reduce the absorption of Vitamin B12 from food, so be sure to check with your doctor or pharmacist if you are taking prescription medications, to see if you should take a vitamin B12 supplement.
Vitamin B12 is an essential B vitamin that our bodies cannot naturally produce. It is found in foods originating from animals and in smaller amounts in some non-animal sources. Supplementing with vitamin B12 may be important for vegetarians, vegans, and older adults who may not absorb nutrients as easily. There is no upper limit for vitamin B12, and most supplements provide between 500 mcg to 5,000 mcg of B12 daily to meet various nutritional needs .
Amy has an MFA in Creative Writing from Antioch University in Los Angeles and is a credentialed English teacher, though she left the classroom to write full time. She especially enjoys creating educational content about health, wellness, and nutrition. Her happy place is in the kitchen, and when not writing, you can find her trying out “kid-friendly recipes” and “healthy desserts for chocolate lovers” from her Pinterest board.
Senior Manager, Medical and Scientific Communications
Melissa is a Registered Dietitian and provides leadership to Pharmavite’s Medical and Scientific Education team. She has over 20 years of experience educating consumers, healthcare professionals, retailers and employees about nutrition, dietary supplements, and overall wellness. Prior to joining the Medical and Scientific Communications team, Melissa launched and managed Pharmavite’s Consumer Affairs department and worked as a clinical dietitian throughout Southern California. Melissa received her Bachelor of Science degree in Nutritional Sciences from the University of Arizona in Tucson, Arizona, and completed her dietetic internship at Veteran’s Hospital in East Orange New Jersey.