Vitamin B12

Vitamin B12 is a nutrient that helps to keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells. There are two steps that are required for the body to absorb vitamin B12 from food. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body. Some people have pernicious anemia, a condition in which they cannot make intrinsic factor. As a result, they have trouble absorbing vitamin B12 from all foods and dietary supplements.

Vitamin B12 deficiency affects between 1.5% and 15% of the public. Symptoms of vitamin B12 deficiency can include: tiredness, weakness, constipation, loss of appetite, weight loss, and megaloblastic anemia. One can also have numbness/ tingling, balance issues, depression, confusion, dementia, poor memory, and mouth/ tongue soreness. Vitamin B12 deficiency can damage the nervous system even in people who don’t have anemia, so it is important to treat a deficiency as soon as possible.


How much vitamin B12 do I need?

Life Stage

Recommended Amount

Birth to 6 months

0.4 mcg

Infants 7–12 months

0.5 mcg

Children 1–3 years

0.9 mcg

Children 4–8 years

1.2 mcg

Children 9–13 years

1.8 mcg

Teens 14–18 years

2.4 mcg


2.4 mcg

Pregnant teens and women

2.6 mcg

Breastfeeding teens and women

2.8 mcg



Some people are more prone to vitamin B12 deficiency. This population includes older adults, those with low hydrochloric acid in their stomach, pernicious anemia, those who have had gastrointestinal surgery, and those who eat little/ no animal foods such as vegetarians and vegans.

Vitamin B12 may have great health benefits including reducing homocysteine levels which may help prevent both heart disease and dementia. It may also help with one’s energy levels and athletic performance.

Simply Nutrients offers a number of Vitamin B12 supplements to meet your dietary needs.


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