Allergy to prescribed 400 mg of B2 riboflavin?

Posted by robindancer5678 @robindancer5678, Jul 22, 2023

I was newly diagnosed with small fiber poly neuropathy. My neurologist put me on 400 mg of vitamin B2 in addition to 400 mg of magnesium. About two weeks later, I experienced what felt like being electrocuted from my toes to my pelvis with extreme itching including both arms and needles in my torso. All day long. At first, I thought it was an extreme exacerbation of the polyneuropathy, but then I stopped the riboflavin as I wondered if it was an allergic response. The electrocution stopped after two days of stopping B2. Has anyone else had an allergic response to riboflavin or magnesium, and what did you do about treating your poly neuropathy?

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John, Volunteer Mentor | @johnbishop | Jul 22, 2023

You might want to give your neurologist a call and discuss this symptoms. I did find this information on precautions with B2.

"Precautions
Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Riboflavin is generally considered safe, even at high doses. Riboflavin does not seem to cause any serious side effects. Very high doses may cause:

- Itching
- Numbness
- Burning or prickling sensations
- Yellow or orange urine
- Sensitivity to light"
--- Vitamin B2 (Riboflavin): https://www.mountsinai.org/health-library/supplement/vitamin-b2-riboflavin

Have you discussed your question with your neurologist who prescribed the B2?

scolio | @scolio | Jul 22, 2023

There is a lot on this page, in the link below, but one of them is about a reaction to riboflavin.
What you were taking was an exceptionally high dose. I wouldn't be surprised if it was at least partly behind the symptoms you had, and I hope you can talk to the physician and that they will listen to you.
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/riboflavin