Vitamins are compounds that you must have for growth and health. They are needed in small amounts only and are usually available in the foods that you eat. Vitamin B 12 is necessary for healthy blood. Cyanocobalamin and hydroxocobalamin are man-made forms of vitamin B 12.
Some people have a medical problem called pernicious anemia in which vitamin B 12 is not absorbed from the intestine. Others may have a badly diseased intestine or have had a large part of their stomach or intestine removed, so that vitamin B 12 cannot be absorbed. These people need to receive vitamin B 12 by injection.
Some conditions may increase your need for vitamin B 12. These include:
In addition, persons that are strict vegetarians or have macrobiotic diets may need vitamin B 12 supplements.
Increased need for vitamin B 12 should be determined by your health care professional.
Lack of vitamin B 12 may lead to anemia (weak blood), stomach problems, and nerve damage. Your health care professional may treat this by prescribing vitamin B 12 for you.
Claims that vitamin B 12 is effective for treatment of various conditions such as aging, allergies, eye problems, slow growth, poor appetite or malnutrition, skin problems, tiredness, mental problems, sterility, thyroid disease, and nerve diseases have not been proven. Many of these treatments involve large and expensive amounts of vitamins.
Injectable vitamin B 12 is given by or under the supervision of a health care professional. Some strengths of oral vitamin B 12 are available only with your health care professional's prescription. Others are available without a prescription.
For good health, it is important that you eat a balanced and varied diet. Follow carefully any diet program your health care professional may recommend. For your specific dietary vitamin and/or mineral needs, ask your health care professional for a list of appropriate foods. If you think that you are not getting enough vitamins and/or minerals in your diet, you may choose to take a dietary supplement.
Vitamin B 12 is found in various foods, including fish, egg yolk, milk, and fermented cheeses. It is not found in any vegetables. Ordinary cooking probably does not destroy the vitamin B 12 in food.
Vitamins alone will not take the place of a good diet and will not provide energy. Your body also needs other substances found in food, such as protein, minerals, carbohydrates, and fat. Vitamins themselves often cannot work without the presence of other foods.
The daily amount of vitamin B 12 needed is defined in several different ways.
Normal daily recommended intakes in micrograms (mcg) for vitamin B 12 are generally defined as follows:
|Infants birth to 3 years of age||0.3–0.7||0.3–0.4|
|Children 4 to 6 years of age||1||0.5|
|Children 7 to 10 years of age||1.4||0.8–1|
|Adolescent and adult males||2||1–2|
|Adolescent and adult females||2||1–2|
If you are taking a dietary supplement without a prescription, carefully read and follow any precautions on the label. For these supplements, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Problems in children have not been reported with intake of normal daily recommended amounts.
Problems in older adults have not been reported with intake of normal daily recommended amounts.
It is especially important that you are receiving enough vitamins when you become pregnant and that you continue to receive the right amount of vitamins throughout your pregnancy. Healthy fetal growth and development depend on a steady supply of nutrients from mother to fetus. However, taking large amounts of a dietary supplement in pregnancy may be harmful to the mother and/or fetus and should be avoided.
You may need vitamin B 12 supplements if you are a strict vegetarian (vegan-vegetarian). Too little vitamin B 12 can cause harmful effects such as anemia or nervous system injury.
It is especially important that you receive the right amounts of vitamins so that your baby will also get the vitamins needed to grow properly. If you are a strict vegetarian, your baby may not be getting the vitamin B 12 needed. However, taking large amounts of a dietary supplement while breast-feeding may be harmful to the mother and/or baby and should be avoided.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of dietary supplements in this class. Make sure you tell your doctor if you have any other medical problems, especially:
If you are taking vitamin B 12 intranasal gel:
For patients receiving vitamin B12 by injection for pernicious anemia or if part of the stomach or intestine has been removed:
The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
If you miss taking a vitamin for one or more days there is no cause for concern, since it takes some time for your body to become seriously low in vitamins. However, if your health care professional has recommended that you take this vitamin, try to remember to take it as directed.
Keep out of the reach of children.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Do not keep outdated medicine or medicine no longer needed.
Along with its needed effects, a dietary supplement may cause some unwanted effects. Vitamin B12 does not usually cause any side effects.
Check with your doctor immediately if any of the following side effects occur:
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.