Is it possible to get too much of a good thing? When that good thing is vitamin B12, a nutrient essential for maintaining blood cell health and nerve function, the answer is “maybe.” Just how much vitamin B12 is too much? Learn more about the safe limits of vitamin B12 and potential side effects.
What is Vitamin B12?
Also known as cobalamin, vitamin B12 is one of eight B vitamins. Vitamin B12 plays a crucial role in the development and function of the central nervous system, as well as the formation of healthy red blood cells and DNA synthesis.
Recommended Daily Intake of Vitamin B12
The recommended daily Intake of vitamin B12 depends on various personal factors such as age and gender. As per the National Institutes of Health, the Recommended Daily Allowances (RDA) for vitamin B12 are:
| Age | Male | Female | Pregnancy | Lactation |
| 0 to 6 months | 0.4 mcg | 0.4 mcg | ||
| 7 to 12 months | 0.5 mcg | 0.5 mcg | ||
| 1 to 3 years | 0.9 mcg | 0.9 mcg | ||
| 4 to 8 years | 1.2 mcg | 1.2 mcg | ||
| 9 to 13 years | 1.8 mcg | 1.8 mcg | ||
| 14 to 18 years | 2.4 mcg | 2.4 mcg | 2.6 mcg | 2.8 mcg |
| 19 years and up | 2.4 mcg | 2.4 mcg | 2.6 mcg | 2.8 mcg |
Natural Sources of Vitamin B12 vs. Supplements
Natural sources of vitamin B12 include:
- Dairy products
- Eggs
- Fish
- Fortified cereals
- Meat
- Poultry
Plant-based foods do not contain natural sources of vitamin B12, so vegetarians and vegans must supplement to ensure adequate intake.
When it comes to bioavailability, dairy products are about three times higher than other natural vitamin B12 sources. However, vitamin B12 bioavailability from supplements is roughly 50 percent higher than that of natural sources.
One caveat: Since vitamin C supplementation can reduce the body’s amounts of B12, wait two or more hours after taking a vitamin B12 supplement to take a vitamin C supplement.
Symptoms of Vitamin B12 Deficiency
Approximately 15 percent of the U.S. population suffers from vitamin B12 deficiency. The deficiency is generally the result of a poor diet, excessive alcohol consumption, or Crohn’s disease. Symptoms include:
- Appetite loss
- Confusion
- Constipation
- Depression
- Mouth sores
- Weight loss
Vitamin B12 Deficiency and Pregnancy
Vitamin B12 is more than safe for pregnant women. It is actually recommended for most of them.
Pregnant women, especially those consuming plant-based diets, are at greater risk of experiencing miscarriage, preterm birth, or pre-eclampsia, and their babies are at higher risk of neural tube defects.
The babies of vitamin B-12 deficient women who decide to breastfeed are more likely to experience developmental delays, along with anemia and failure to thrive.
Certain medications may decrease the body’s ability to absorb vitamin B12. These medications include:
- Paser, or amino salicylic acid for digestive problems
- Colchicine and other anti-inflammatories for the treatment of gout
- Metformin and other diabetes drugs
- Proton pump inhibitors, such as Prilosec or Prevacid, for stomach acid reduction
Vitamin B12 Deficiency Anemia
Some people suffer from vitamin B12 deficiency anemia, resulting in insufficient number of red blood cells. As per John Hopkins Medicine, this type of anemia is more common in those with Northern European ancestry. Patients who have had the end of their small intestine removed or bypassed via surgery or had all or part of their stomach removed are especially vulnerable. Other risk factors for vitamin B12 deficiency anemia include:
- Autoimmune diseases
- Type 1 diabetes
- HIV
- Aging
- Vitamin B12 deficiency anemia symptoms include:
- Balance issues
- Muscle weakness
- Tachycardia, or rapid heart rate
- Tender or smooth tongue
- Tingling or numbness in the hands and feet
How Much Vitamin B12 is Too Much?
Can you take too much vitamin B? For the most part, excessive vitamin B12 intake does no harm. Because vitamin B12 is water-soluble, excess amounts are excreted via urine. Most people are just fine even if taking vitamin B12 amounts dozens of times the RDA.
There are exceptions to the considerable safety factor when patients take very high doses of vitamin B12, the kind the doctor may recommend for those battling a deficiency.
While the vitamin is well-tolerated and generally free of side effects, there is no advantage to taking excess amounts of B12. Very high amounts of B12, unless a deficiency is involved, do not correspond to superior immunity or other benefits.
Potential Side Effects of Excessive B12 Intake
The following side effects are possible if taking large amounts of vitamin B12:
- Skin issues: Too much vitamin B12 consumption can result in certain skin disorders, including acne and rosacea.
- Gastrointestinal problems: Nausea, vomiting, or diarrhea may indicate excessive vitamin B12 consumption.
- Diabetes and kidney disease complications: Those with compromised kidneys due to diabetes may experience faster deterioration if taking too much B12.
In rare cases, large amounts of vitamin B12 over a substantial period of time can increase bone fracture risk.
How IV Therapy Helps Maintain Optimal Vitamin B12 Levels
Everyone needs the right amount of vitamin B12 to maintain red blood cell protection and neurological function. The best way to do so is by IV therapy.
Oral vitamin B12 is not well absorbed by the body. It must pass through the gastrointestinal tract before entering the bloodstream, significantly reducing absorption levels. With IV therapy, vitamin B12 directly enters the bloodstream, substantially improving absorption.
Vitamin B12 IV therapy is both safe and effective.
Vitamin B12 IV Therapy With Reset IV
For optimal health and the proper amount of vitamin B12 for your needs, schedule vitamin B12 IV therapy with Reset IV. Our registered nurses arrive at your home, place of business, or hotel room within one hour of your scheduling the appointment.
Our experienced staff will answer your questions before your treatment session. We can customize your treatment, adding additional vitamins and minerals based on your individual needs.
Book an appointment now, and expect a nurse to arrive at your destination within an hour. We’re available 24/7, and there are no travel fees. Schedule your appointment now and pay later!