What Are The Side Effects Of Vitamin B12?

Basic concepts of Vitamin B12

Vitamin B12 is an essential vitamin for the human body, which means that the body needs Vitamin B12 to function properly.

Meat, fish, dairy products, and other foods contain Vitamin B12 which can also be synthesized in the laboratory, usually in combination with other vitamin B. Do you know what are the side effects of Vitamin B12?


Oral Vitamin B12 can used to treat pernicious anemia, which is severe anemia caused by Vitamin B12 deficiency, which usually occurs in the elderly.

Oral Vitamin B12 can also be used to treat memory loss, Alzheimer’s Disease, and slow down aging, Boost mood, spirit, attention, improve mental function and immune system, heart disease, cardiovascular blockage, reduce the risk of postoperative arterial occlusion, Triglyceride is too high, reduce homocysteine ​​levels (a type of Heart-causing substances), male infertility, Diabetes, Diabetic Nerve Damage, nerve damage to hands or feet, sleep disorders, depression, mental disorders, Schizophrenia, Osteoporosis, tendon edema, AIDS, intestinal inflammation, diarrhea, Asthma, allergy And a disease called skin disease and a skin infection called Vitiligo.

Oral Vitamin B12 can also be applied to Amyotrophic Lateral Sclerosis (also known as Lou Gehrig’s disease), Multiple Sclerosis, prevention of Age-Related Macular Degeneration, excessive thyroid secretion, Lyme Disease, and Gum Disease, respiratory tract infections, fertility maintenance, Ringing in the Ears, Bleeding, liver and kidney problems, Canker Sores, fracture prevention, Stroke, blood clots, and toxins and allergens in tobacco.

Oral Vitamin B12 can also prevent cancers such as breast cancer, cervical cancer, colorectal cancer, and lung cancer.

Vitamin B12 is used directly on the skin or with avocado oil to treat Psoriasis and Eczema.

Vitamin B12 nasal soft gel can treat pernicious anemia and prevent and treat Vitamin B12 deficiency.


Vitamin B12 injection can treat pernicious anemia, prevent and treat Vitamin B12 deficiency, and prevent and treat neurological diseases such as cervical spondylotic myelopathy, which may occur when Vitamin B12 is deficient.

Vitamin B12 is also used to treat tremor, Vitamin B12 selective absorption disorder, cyanide poisoning, nerve damage caused by shingles (shingles), nerve damage caused by diabetes, fatigue, chronic fatigue syndrome, type C Hepatitis, conditions caused by high thyroxine, bleeding, cancer, psoriasis, and liver and kidney diseases.

It will also be injected into the body to prevent occlusion of the artery after surgery.

The function principle of Vitamin B12

There is not enough research to show the efficacy principle of Vitamin B12. If you need further information, please discuss with your doctor or herbalist.

However, it is now known that the brain, nerves, blood cells, and many parts of the body require Vitamin B12 for proper function and development.


If you encounter the following conditions, please consult a physician, pharmacist, or herbalist first to determine the suitability of Vitamin B12:

  • During pregnancy or breastfeeding.
  • Are taking other medicines.
  • Allergy to Vitamin B12 ingredients, other medicines, or other herbs.
  • Suffering from other diseases, illnesses, or physical conditions.
  • There are other allergic symptoms, such as allergies to food, dyes, preservatives, or animals.

Compared with the regulation of medicines, the regulation of herbal medicines is less strict, and more research is needed to prove its safety.

Before use, please make sure that the benefits outweigh the risks. It is recommended to consult an herbalist or physician for more information.

Is it safe to use Vitamin B12

In general, Vitamin B12 is safe for oral, topical, inhalation, injection, or injection; it is safe to use even in large doses.

Special considerations

Pregnancy and breast-feeding: Vitamin B12 taken orally at the recommended dosage is safe for pregnant and breastfeeding women. The recommended oral dosage for pregnant women is 2.6 micrograms (mcg) per day.

Women who are breastfeeding should eat more than 2.8 micrograms per day. The safety of this dose is still unknown.

After stent placement: After using coronary stent surgery, avoid the use of Vitamin B12, Folate, and Vitamin B12 combination drugs, as this will increase the risk of stenosis.

Allergies to Cobalt or Cobalamin: Do not use Vitamin B12.

Leber’s Hereditary Optic Atrophy (Leber’s Disease): A hereditary eye disease. Do not use Vitamin B12 if it is present, as Vitamin B12 can severely damage the optic nerve and cause blindness.

Abnormal Red Blood Cells (also known as Megaloblastic Anemia): Giant embryo red blood cell anemia can sometimes be treated with Vitamin B12, but there may be serious side effects. If there is no close monitoring by medical care staff, please Do not rely on Vitamin B12 treatment.

The number of red blood cells is too high (Polycythemia Vera): Treatment of Vitamin B12 deficiency symptoms may cause symptoms of polycythemia vera.

Potential side effects of using Vitamin B12

Studies have indicated that people who use special avocado oil and Vitamin B12 lotion to treat psoriasis may experience slight itching.

Not everyone will experience these side effects, and some side effects are not listed above. If you have any concerns about side effects, please consult your herbalist or physician.

Potential interactions with Vitamin B12

Vitamin B12 may interact with the medication or physical condition you are taking. Please consult your physician or herbalist before use.

Products that will potentially interact with Vitamin B12 include:

Chloramphenicol: Vitamin B12 plays an important role in making new blood cells, while chloramphenicol reduces new blood cells.

Long-term use of Chloramphenicol may reduce the effect of microbiota B12 on blood cells, but most people will only use chloramphenicol for a short period of time, so this interaction will not cause major problems.

The recommended dosage of Vitamin B12

The following information is not a medical diagnosis, please consult a physician or herbalist before using.

What is the general usage of vitamin B12



The typical intake of Vitamin B12 is 1 to 25 micrograms per day: the recommended daily intake is 1.8 micrograms; 2.4 micrograms for older children and adults, 2.6 micrograms for pregnant women, and 2.8 micrograms for breastfeeding women.

Because 10% to 30% of the elderly cannot effectively obtain Vitamin B12 through food, these people over the age of 50 need to obtain the recommended daily intake by eating fortified Vitamin B12 food or using Vitamin B12 supplements the amount.

The elderly use supplements containing 25-100 intakes daily to maintain Vitamin B12 levels.

For Vitamin B12 deficiency or pernicious anemia: currently using 300-10,000 micrograms of Cyanocobalamin per day. However, some evidence shows that the most effective oral dose is 647-1032 micrograms per day.

For high levels of homocysteine ​​in the blood: 400-500 mcg Vitamin B12 with 0.54-5 mg of folic acid and 16.5 mg of pyridoxine.

For the prevention of macular degeneration: Vitamin B12 1 mg, folic acid 2.5 mg, and daily use of pyridoxine 50 mg.

For external use:

Ectopic dermatitis (Eczema, also known as eczema): Use cream containing 0.07% Vitamin B12, applied twice daily.

Psoriasis: Use a special cream containing avocado oil, plus 0.7 mg of Vitamin B12, used twice a day for 12 weeks.

The form of injection:

Pernicious anemia: The permissible dosage for pernicious anemia is intramuscular or subcutaneous injection, 100 micrograms at a time, for 6 to 7 days.

Then the 7 doses can be divided into one-day intervals and then changed to use every 3 to 4 days for a period of 3 weeks. For the rest of his life, he should maintain a monthly dose of 100 micrograms intramuscularly or subcutaneously.

Vitamin B12 deficiency: The usual dosage is 30 micrograms of intramuscular or subcutaneous injections for 5 to 10 days. For continuous treatment, it is generally once a month, each time using 100 ~ 200 micrograms.

Usually, two types of products, cyanocobalamin, and hydroxocobalamin are used for injection.

Hereditary Vitamin B12 malabsorption: It will be injected into the muscle in the form of hydroxocobalamin, 1 mg daily for 10 days, and then tracked according to the patient’s condition every month.

Cyanide poisoning: Hydroxycobalamin (Cyanokit, cyanide antidote) up to a total of 10 grams


For pernicious anemia and Vitamin B12 deficiency: 500 micrograms of Vitamin B12 is administered weekly from one side of the nasal cavity.

Subcutaneous injection:

For nerve damage caused by herpes zoster: 1000 μg of Vitamin B12 is injected subcutaneously, 100 mg of thiamine may be added and administered 6 times within 4 weeks.



The recommended daily dosage of Vitamin B12 is:

    • Infants from 0 to 6 months: 0.4 micrograms
    • Infants from 7 to 12 months: 0.5 mcg
    • Children 1~3 years old: 0.9 mcg
    • Children 4-8 years old: 1.2 mcg
    • Children 9-13 years old and above: 1.8 mcg


Pernicious anemia: daily intramuscular or subcutaneous injection of 30 to 50 micrograms for more than 2 weeks, with a total dosage of 1000 to 5000 micrograms, followed by 100 micrograms every 4 weeks.

Vitamin B12 deficiency: intramuscular or subcutaneous injection of 100 micrograms once a day for 10 to 15 days, followed by 1 to 1 times a week, 60-100 micrograms each time for several months.

The dosage of Vitamin B12 varies from person to person, mainly affected by age, health status, and other diseases; and this type of herbal supplement is not necessarily safe.

Therefore, please consult your physician or herbalist to know the dosage suitable for you before taking it.

What are the manufactured products of Vitamin B12?

Vitamin B12 is manufactured in the following forms:

  • Natural food
  • capsule
  • Tablets

Where can I buy the best Vitamin B12 supplements?

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Vitamin B12

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