Although it doesn’t have anything to do with popularity (except for you can only be popular if you’re alive), I feel that I should write about niacin grapefruit interaction because when I had a severe reaction, I couldn’t find anything on the internet about the topic. I’m not a doctor or a scientist. This article just explains my experience with a niacin grapefruit interaction. Let’s just say it wasn’t fun.
The other day I took a gram (1000mg) of non-prescription niacin (Vitamin B3). I don’t take this vitamin regularly, but I was congested and niacin helps loosen mucus for me. I was a little flushed and had the usual niacin related side effects. They aren’t terribly fun, but I’d dealt with them before.
About an hour later, I ate an entire grapefruit. It was a fairly large one. That started what I can only surmise was a bad niacin grapefruit interaction. I started to get what I thought was the chills. In reality, it was my muscles shaking. I walked down the stairs and was shaking so badly I could barely stay upright. My muscle spasms were so extreme that I was becoming nearly rigid. I talked to my dad who is an EMT and told him what was wrong. By that point, I was getting a little short of breath and could hardly talk. I stood still while he took my pulse, but my entire body was shaking.
My heart was at around 80 beats per minute. While not objectively bad, my usual pulse is close to fifty. I was also beginning to panic slightly because I just could not stop shaking no matter what I tried.
I induced vomiting, then drank lots and lots of water. The shaking slowed down considerably. After a hot bath, lots more water, and a couple hours of waiting, my muscles had largely returned to normal. The niacin grapefruit interaction seemed to have ended. I felt generally bad for a couple of days afterwards too.
If you’re wondering whether you should eat grapefruit or grapefruit juice while taking a niacin supplement, my advice is don’t do it. I can’t prove it was a niacin grapefruit interaction which caused my symptoms. But, given that grapefruit interacts with numerous medicines, it seems to be the case. Although everyone reacts differently, my experience was absolutely horrible. I worried that the reaction would put me in the hospital or even kill me. If you’re taking niacin of any kind, avoid the grapefruit.