The best form of B12 is generally considered to be methylcobalamin, the natural form.
Methylcobalamin vs. Cyanocobalamin
There are different forms of Vitamin B12 available in supplements, with the two most common being methylcobalamin and cyanocobalamin. According to Harvard Health, Dr. Stampfer recommends the natural form, methylcobalamin, over the synthetic form, cyanocobalamin.
- Methylcobalamin: This is the naturally occurring form of B12 found in food.
- Cyanocobalamin: This is a synthetic form that the body must convert to methylcobalamin or adenosylcobalamin to be used.
Why Methylcobalamin May Be Preferred
The preference for methylcobalamin stems from concerns about cyanocobalamin, particularly for individuals with kidney issues.
- Kidney Function: Dr. Stampfer notes that "studies suggest cyanocobalamin may impair kidney function in people with borderline kidney problems, so it's better to stay on the safe side". This suggests that methylcobalamin is a safer option, especially for those with pre-existing kidney conditions.
Summary Table: B12 Forms
| Feature | Methylcobalamin (Natural) | Cyanocobalamin (Synthetic) |
|---|---|---|
| Form | Natural | Synthetic |
| Kidney Concerns | Lower | Higher, especially with pre-existing kidney issues. |
| Recommendation | Generally preferred | Less preferred |
