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Vitamin injections or supplements: how do I decide?
Written by the Forever Young IV Bar teamPublished
For people with a confirmed B12 deficiency, a Cochrane review found B12 pills and B12 shots had similar effects on blood B12 levels, though the evidence was low quality. Shots may matter most for people who cannot absorb B12 well. Supplements are less strictly regulated than medicines, so tell your provider what you take.
Why some people need more than food or pills
Most people get B12 from food. Cleveland Clinic explains that to absorb B12 from food, stomach acid first frees it from the food and then it combines with a protein your stomach makes, called intrinsic factor. After that your digestive system can absorb it.
MedlinePlus says B12 deficiency happens when the body does not get, or cannot absorb, enough B12. It is most common in people over 50, people who follow a vegetarian or vegan diet, people who have had stomach or intestinal surgery, and people with digestive conditions such as celiac disease or Crohn disease.
In pernicious anemia, the stomach does not make enough intrinsic factor, so the intestine cannot absorb B12 properly. MedlinePlus says treatment often involves a shot of B12 once a month, and some people may be treated with large doses by mouth.
What the research says about B12 pills vs shots
A Cochrane review looked at three randomized trials with 153 people comparing B12 by mouth with B12 shots for B12 deficiency. In two trials using 1000 mcg a day by mouth, there was no clinically relevant difference in blood B12 levels compared with the shots. The review rated the evidence as low quality because there were few trials and few people.
An Ontario health technology review reached a similar view and called its evidence moderate quality: oral B12 was as effective as injected B12 in people with confirmed B12 deficiency. Cleveland Clinic lists oral medicine, injections, a nasal spray or gel, and eating more B12-rich foods as treatment options, and says your provider chooses based on the cause.
These studies were in people with a confirmed deficiency. They do not show what a shot does for someone whose B12 is already normal.
What to know about supplements
The National Center for Complementary and Integrative Health (NCCIH) says rules for making and selling dietary supplements are less strict than those for prescription or over-the-counter drugs, and that the FDA is not authorized to review dietary supplements for safety and effectiveness before they are marketed. It also says what is on a supplement label may not be what is in the product, and that supplements may interact with medicines.
Tell your provider about every vitamin and supplement you take. MedlinePlus also notes that supplements can affect some lab test results.
How to decide with your provider
Questions to bring to your provider:
- Do I have a reason to think my B12 is low, such as my age, diet, surgery or a digestive condition?
- Would a blood test show whether I need treatment?
- If my level is low, would pills, shots or both make sense for me?
- Could any of my medicines or supplements affect this?
- How will we know if it is working?
Book a visit or ask a question
We offer a vitamin B12 shot at our Plano studio, and a provider can help you decide whether it fits. You can book online at foreveryoungivbar.com/book/ or call 469-613-7033. Our Plano studio is at 2609 Technology Drive, Suite 108 (inside Habitat Commons). A nurse can also come to you for mobile visits across Dallas-Fort Worth, which are booked by phone.
Sources
- MedlinePlus Medical Encyclopedia: Vitamin B12
- MedlinePlus Medical Encyclopedia: Pernicious anemia
- Wang et al.: Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency
- Vitamin B12 and cognitive function: an evidence-based analysis
- NCCIH: Dietary and herbal supplements
- Cleveland Clinic: Vitamin B12 deficiency
- MedlinePlus: How to understand your lab results