Vitamin B12 Dosage: How Much Should You Take Each Day?

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Vitamin B12 is a water-soluble nutrient that is essential for the body's growth and development. The ideal dose of vitamin B12 varies by gender, age, and the reason for taking the medication. So how much vitamin B12 should you take per day?

1. Why is vitamin B12 needed?

Vitamin B12 is an essential nutrient and plays an important role in many processes taking place inside the body. Vitamin B12 is necessary for the production of red blood cells, the formation of DNA gene sequences, and is involved in nerve function as well as metabolism of the body. Vitamin B12 also plays an important role in lowering levels of an amino acid called homocysteine, which is directly linked to chronic diseases such as cardiovascular disease, stroke and Alzheimer's. In addition, vitamin B12 is also very actively involved in the process of energy production. However, they do not play a decisive role, so there is no evidence that vitamin B12 supplementation can increase dietary energy in malnourished or chronically deficient subjects.
Vitamin B12 is found mainly in foods of animal origin including meat, seafood and egg and dairy products. In addition, cereals are also a notable source of vitamin B12 for those following a vegetarian diet.
The human body can store vitamin B12 for up to several years so moderate and severe deficiency of this vitamin is very rare but studies show that up to 26% of the population worldwide mild vitamin B12 deficiency. Over time, vitamin B12 deficiency can lead to dangerous complications such as anemia, irreversible damage to the nervous system, and chronic malnutrition or lack of energy.

There are 2 main causes of a person's vitamin B12 deficiency: not getting enough of this vitamin in the daily diet and using certain foods or medications that interfere with the body's absorption of vitamin B12. Meanwhile, the direct causes of vitamin B12 deficiency include:
Follow a vegetarian or vegan diet, especially for people over 50 years old; Digestive disorders include Crohn's disease (an inflammatory bowel disease with symptoms of abdominal pain, severe diarrhea, fatigue, weight loss, malnutrition...) or Gluten intolerance (a protein found in in wheat and some other grains such as barley or rye); Performing gastrointestinal surgery, abdominal liposuction surgery or removal of intestines, appendix...; Using certain drugs in the treatment of diabetes such as Metformin or some drugs that regulate the level of acid in the stomach; People with certain forms of genetic mutations such as heterozygous mutations in the MTHFR, MTRR, and CBS genes; Excessive use of wine, beer and other alcoholic beverages.
If you belong to one of the risk groups leading to vitamin B12 deficiency mentioned above, you should immediately take B12 supplements as directed by your doctor to ensure the normal development of the body, prevent complications. danger may occur.
There is also another reason that shows the need for vitamin B12 supplementation that is its ability to enhance memory. Animal studies have shown that B12 deficiency is responsible for memory impairment. In addition, this vitamin can also prevent the recurrence of depressive symptoms.

2. What is the daily dose of vitamin B12?

The recommended daily dose for vitamin B12 in people 14 years of age and older is 2.4 micrograms. However, depending on a number of factors such as age, gender, lifestyle, or excess or deficiency of B12, the recommended amount may change.
It should be noted that the body's ability to absorb vitamin B12 is relatively low. Only 10 micrograms out of a total of 500 micrograms of B12 are absorbed through our daily foods that are absorbed by our bodies. That is only at 2%.
Here are some recommended daily doses of vitamin B12 for specific situations:
People under 50: For people between 14 and 50 years of age, the recommended dose of vitamin B12 is 2.4 micrograms/day. . Most people in this age group get adequate levels of B12 through the foods they consume every day.
Example: A person eats 2 eggs for breakfast (1.2 micrograms B12), 85 grams of tuna for lunch (2.5 micrograms B12) and 85 grams of beef for dinner (1.4 micrograms B12). That is, they were given 5.1 micrograms of B12 a day, more than 2 times the recommended amount. Therefore, vitamin B12 supplementation for people in this age group is not necessary unless they have any factors that interfere with the absorption of this vitamin.
People over 50: Elderly people are more susceptible to vitamin B12 deficiency. Many studies have shown that up to 62% of people over the age of 65 have lower than normal blood levels of vitamin B12. As the body ages, they secrete more acid as well as stomach intrinsic factor – both of which affect the body's ability to absorb vitamin B12. Therefore, the American Academy of Medicine recommends that people over 50 years of age, in addition to the source of B12 provided by daily foods, should be supplemented with this vitamin through functional foods or taking vitamin B12 directly.

Pregnant women: Pregnant women have a higher need for vitamin B12 than the general population. Mothers who are deficient in B12 can lead to some birth defects in the fetus. In addition, B12 deficiency also carries a risk of premature birth and low birth weight in babies. The recommended dose of vitamin B12 in pregnant women is 2.6 micrograms/day and they can be fully provided through the daily diet of pregnant women.
Lactating women: Vitamin B12 deficiency in nursing mothers can lead to growth retardation in the child. The recommended dose of B12 for nursing women is slightly higher than for pregnant women, at 2.8 micrograms per day. Vegetarians or vegans: People following a vegetarian diet still need to ensure the recommended dose of B12 is 2.4 micrograms/day, although this is difficult to do. In the study of vitamin B12 in vegetarians, up to 86.5% of study subjects had lower than normal levels of B12. Therefore, vitamin B12 supplementation in this group of subjects is essential.
For those who need to increase the level of energy in the diet: According to the World Health Organization WHO, people who are malnourished or have a chronic lack of energy due to vitamin B12 should take 1 mg of B12 daily for the first month, then maintain the dose from 125 to 250 micrograms in the following months. In the process of supplementing B12, some side effects should be noted:
Vitamin B12 injection can lead to skin inflammation and acne; High doses of vitamin B12 above 1000 micrograms may worsen complications in people with kidney disease; Excessively high levels of B12 in the blood of pregnant or nursing mothers are at risk of developing autism in children.

Vitamin B12 is a nutrient that plays an essential role in many bodily functions. The recommended dose of vitamin B12 ranges from 2.4 micrograms to 2.8 micrograms depending on the user. Most people can meet this dose through daily diet, however for the elderly, vegetarians or those with impaired absorption of B12, it is recommended to take directly or supplement this vitamin. is very necessary.
To know if your body is excess or deficient in vitamin B12, you should go for regular health check-ups to protect your overall health. Currently, Vinmec International General Hospital has general health checkup packages suitable for each age, gender and individual needs of customers with a reasonable price policy, including:
Health checkup package diamond general health checkup package Vip special health checkup package Comprehensive health checkup package Standard general health checkup package Patient's examination results will be returned to your home. After receiving the results of the general health examination, if you detect diseases that require intensive examination and treatment, you can use services from other specialties right at the Hospital with quality treatment and services. outstanding customer service.
To register for examination and treatment at Vinmec International General Hospital, you can contact the nationwide Vinmec Health System Hotline, or register online HERE.
References: healthline.com, hopkinsmedicine.org, health.harvard.edu