After reading Iodine and why you need it years ago, I started taking b2 and b3 in conjunction with iodine.

No matter what type of niacin I use I get a flush. Sometimes it is so bad I look like I aged 40 years and turn into red skull from Captain America.

I am only taking a methylated b vitamin complex now that contains 50mg of niacin in the half serving I take. If I take it 2 days in a row I flush.

What causes this flush? I've seen people taking 1000 mg doses and can't imagine doing that. I'd literally want to crawl out of my skin.

Anyone know what it is that triggers the flush? My searches online have come up empty handed as to the pathways that trigger this.