Hi,
Niacin is a form of vitamin B3 that is often used to treat
high cholesterol levels. While niacin is generally safe when taken at recommended doses, some individuals may experience side effects, especially when taking high doses. The symptoms you are experiencing, including sharp jabbing pain under the left arm, headache,
stomach discomfort, and tightness in the throat, could be related to a niacin overdose or
hypersensitivity reaction.
Niacin can cause flushing of the skin, which can feel like a prickling or burning sensation, and this may be what you are feeling under your left arm. Other symptoms of a niacin overdose or hypersensitivity reaction may include nausea, vomiting, diarrhea,
dizziness, rapid heartbeat, and
difficulty breathing.
If you continue to experience these symptoms or if they worsen, you should seek medical attention immediately. It's also important to talk to your healthcare provider about any medications or supplements you are taking, including niacin, to ensure that they are safe for you to use and that you are taking them at appropriate doses.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Priyanka, General & Family Physician