What is the recommended dose for Vitamin B12 (Cobalamin) supplementation?

From the Guidelines

The recommended vitamin B12 supplementation dose for most adults is 1,000-2,000 micrograms (mcg) daily for those with deficiency, typically taken orally, as supported by the most recent guidelines 1. When considering vitamin B12 supplementation, it's essential to prioritize the patient's specific needs and health status. For maintenance after correcting a deficiency, 1,000 mcg weekly or 100-500 mcg daily is often sufficient. The choice of formulation, such as cyanocobalamin or hydroxocobalamin, depends on the individual's medical condition and preferences. Some key points to consider when recommending vitamin B12 supplementation include:

• The importance of prompt treatment for vitamin B12 deficiency, especially in cases with possible neurological involvement, as emphasized in the 2020 guidelines 1
• The need for regular monitoring of vitamin B12 levels and adjustment of supplementation doses as necessary
• The potential for interactions with other medications, such as metformin or proton pump inhibitors, which may affect vitamin B12 absorption
• The excellent safety profile of vitamin B12 supplementation, with minimal risk of toxicity even at high doses, as excess is excreted in urine 1. In severe cases of deficiency or malabsorption, B12 injections (typically 1,000 mcg hydroxocobalamin or cyanocobalamin) may be necessary, usually administered every other day for 1-2 weeks, then weekly for a month, followed by monthly maintenance, as recommended in the guidelines 1.

From the FDA Drug Label

Directions Adults 18 years or older: 1,000 mcg (1 tablet) daily preferably with a meal or as directed by your doctor. The recommended B12 supplementation dose for adults 18 years or older is 1,000 mcg daily, preferably with a meal, as directed by the drug label 2.

• For adults, the dose is 1 tablet (1,000 mcg) per day.
• For persons under 18 years of age, it is recommended to consult a doctor for dosage instructions.

From the Research

Vitamin B12 Supplementation Dose

The recommended dose of vitamin B12 supplementation varies depending on the individual's condition and the severity of the deficiency.

• For patients with vitamin B12 deficiency, oral administration of high-dose vitamin B12 (1 to 2 mg daily) is as effective as intramuscular administration for correcting anemia and neurologic symptoms 3.
• Patients who have had bariatric surgery should receive 1 mg of oral vitamin B12 per day indefinitely 3.
• The use of high-dose oral B12 at different frequencies may be considered for long-term treatment 4.
• There is no specific recommendation for a standard supplementation dose, as it depends on the individual's needs and the severity of the deficiency.

Factors to Consider

When considering vitamin B12 supplementation, the following factors should be taken into account:

• Patient lifestyle, disease history, and medications can provide clues to the cause of B12 deficiency 4.
• The severity of clinical symptoms, the causes of B12 deficiency, and the treatment goals govern decisions regarding the route and dose of B12 therapy 4.
• Prophylactic B12 supplementation should be considered for specific high-risk groups, such as vegans or strict vegetarians, and adults older than 75 years 3, 5.

Route of Administration

The route of administration for vitamin B12 supplementation can be either oral or parenteral.

• Oral administration is comparable to intramuscular administration for rectifying vitamin B12 deficiency 3, 6.
• Parenteral administration may be considered for patients with severe deficiency or severe neurologic symptoms 3, 4.