This topic is about understanding the differences between vitamin B12 and folic acid deficiencies, especially for someone who has had an ileostomy for a long time. The person sharing their experience is a 45-year-old who has been living with an ileostomy since they were 25 due to indeterminate colitis. They have been taking folic acid daily for 15 years and have noticed that reducing the dose leads to fatigue and tingling in their legs. They also take children's chewable multivitamins with iron and generally feel well. Here are some questions and insights they have shared:

1. Can vitamin B12 levels still be accurately tested while taking folic acid, since folic acid can mask a B12 deficiency?
2. Has anyone experienced tingling in their legs due to a B12 deficiency?
3. Is sublingual B12 as effective as B12 injections?
4. Any other thoughts or experiences to share?

Additional information includes:
- They have never been diagnosed with anemia but plan to ask their doctor for a complete blood count and other lab tests.
- They believe, based on personal research, that sublingual B12 is effective and has low toxicity, and they plan to discuss this with their doctor.

Here are some helpful pieces of advice and insights:

- It's important to check for anemia and red blood cell count, as low levels due to B12 deficiency can cause fatigue.
- A blood test can measure serum B12 and folate levels even if you are taking folic acid, which helps in making treatment decisions.
- Monthly self-administered intramuscular B12 injections are easy to do, using a very small needle that is virtually painless.
- There are natural or over-the-counter options like sublingual B12 tablets available, and it's a good idea to discuss the best option with your doctor.