From the Guidelines
Vitamin B12 supplements can be taken orally, with a recommended dose of 1 mg daily, as this is the most commonly used dose in current practice and is considered to be at least as effective as lower strength tablets. The decision to use oral vitamin B12 supplementation is based on the most recent evidence from the BMJ study 1, which compared oral and parenteral vitamin B12 treatments and found that oral treatment may be the most cost-effective strategy.
When considering oral vitamin B12 supplementation, it is essential to note that the effectiveness of oral therapy may vary depending on the individual's specific needs and medical history. For example, patients with certain conditions like pernicious anemia, gastrointestinal disorders, or those who have had stomach or intestinal surgeries may have trouble absorbing oral B12 and might require higher doses or injections 1.
The recommended dose of 1 mg daily is based on the guideline committee's agreement that it is reasonable to assume that the higher dosage would be at least as effective as the lower strength tablet 1. Additionally, prescribing a higher dose may be more effective and provide greater health benefit as a larger amount of B12 is being delivered to the bloodstream, and therefore absorbed, while also being convenient to patients by reducing tablet burden.
Key points to consider when taking oral vitamin B12 supplements include:
- The water-soluble nature of B12, which makes it relatively safe even at higher doses
- The importance of consulting with a healthcare provider to determine the appropriate dosage based on individual needs and medical history
- The potential for oral therapy to be as effective as parenteral supplementation, although more research is needed to confirm this 1
From the FDA Drug Label
In patients with Addisonian Pernicious Anemia, parenteral therapy with vitamin B12 is the recommended method of treatment and will be required for the remainder of the patient’s life. Oral therapy is not dependable. Patients who have normal intestinal absorption may be treated with an oral therapeutic multivitamin preparation, containing 15 mcg vitamin B12 daily.
Vitamin B12 supplementation can be taken orally, but only in patients with normal intestinal absorption. The recommended oral dose is 15 mcg daily as part of a therapeutic multivitamin preparation 2.
From the Research
Vitamin B12 Supplementation
- Vitamin B12 supplementation can be taken orally, as studies have shown that oral administration of high-dose vitamin B12 is as effective as intramuscular administration for correcting anemia and neurologic symptoms 3.
- The recommended dose of oral vitamin B12 supplementation varies, but studies have used doses ranging from 1 to 2 mg daily 3 and 1000 μg/d 4, 5.
Efficacy of Oral Vitamin B12 Supplementation
- A prospective cohort study found that oral vitamin B12 supplementation at a dosage of 1000 μg/d was effective in improving vitamin B12 deficiency in patients with pernicious anemia, with 88.5% of patients no longer deficient in vitamin B12 after 1 month of treatment 4.
- A systematic review found that oral vitamin B12 showed similar effects to intramuscular vitamin B12 in terms of normalizing serum vitamin B12 levels, but oral treatment costs less 5.
Patient Perspectives on Oral Vitamin B12 Therapy
- A qualitative and quantitative study found that patients were willing to try oral B12 therapy and were satisfied with the convenience of oral therapy, with 76% of patients who tried oral therapy reporting satisfaction and 71% wishing to permanently switch from injection to oral therapy 6.
- Factors associated with a willingness to switch to oral B12 therapy included convenience, reduced frequency of visits to the healthcare provider, and reduced costs to the healthcare system 6.