From the Guidelines
The recommended oral dose of Vitamin B-12 for patients with low B-12 levels is 250-350 μg/d or 1000 μg/wk sublingual, as stated in the 2017 study published in Advances in Nutrition 1. This dose is recommended for the prevention and treatment of nutritional deficiencies in adult bariatric surgery patients. For patients with a confirmed deficiency, a higher dose of 1000-2000 μg/d sublingual may be necessary, especially after certain types of bariatric surgery such as Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion (BPD) 1. Key points to consider when treating hypocobalaminemia include:
- Oral supplementation is generally effective for most patients with dietary deficiency or food-bound malabsorption
- Patients with severe malabsorption issues may require intramuscular injections instead
- Treatment should continue until clinical improvement occurs and lab values normalize, which may take several months
- Vitamin B-12 supplementation helps reverse symptoms like fatigue, weakness, neurological problems, and prevents progression of potentially irreversible neurological damage. It is essential to note that the specific dose and duration of treatment may vary depending on the individual patient's needs and the severity of their deficiency, and should be determined by a healthcare professional 1.
From the Research
Recommended Oral Dose of Vitamin B-12
The recommended oral dose of Vitamin B-12 (cobalamin) for patients with low B-12 levels (hypocobalaminemia) varies, but several studies provide guidance:
- A daily dose of 300-1000 micrograms may be therapeutically equivalent to parenteral therapy 2
- High-dose vitamin B12 (1 to 2 mg daily) is as effective as intramuscular administration for correcting anemia and neurologic symptoms 3
- 1000 micrograms of oral cyanocobalamin per day can effectively treat older patients with cobalamin deficiency related to nutritional deficiency and food-cobalamin malabsorption 4, 5
- A suggested oral vitamin B12 dose is 1 mg daily for a month, and then a maintenance dose of 125 to 250 µg for patients with dietary insufficiency and 1 mg daily for those with pernicious anaemia 6
Key Considerations
- Oral administration of high-dose vitamin B12 can be an effective alternative to intramuscular injections 3, 4, 5
- Patients older than 50 years and vegans or strict vegetarians should consume foods fortified with vitamin B12 or take vitamin B12 supplements 3
- Patients who have had bariatric surgery should receive 1 mg of oral vitamin B12 per day indefinitely 3