Hi Friends, can niacin be overdosed? Today i received 100 grams of pure niacin powder, with a little spoon that allows one to "measure" ~½ gram. I mixed a cup of mealworms with ~250mg of Niacin, added two teaspoons of glucose, two cups of water, grabbed Limpy Duck and sat down to feed him some extra nutrients. - He has gotten a bit slim these days. Curiosity, one of my other female ducks forgot all dignity and fear and joined us on the patio begging for some treats too - who can resist a greenish orange beak, soft quacks, large blue eyes and webbed feet… While i was feeding some worms to her i did not notice that Limpy gulped down all the mealworms (1 CUP!) and drank half of the water so he may has gotten a dose of >100mg of Niacin. Usually he eats a quarter cup of mealworms, so that would have been ~20mg and the rest would have gone into everybody's supper. He might had been afraid i would give away "his" mealworms and gobbled them all down. That was an hour ago, so far he's doing fine, no signs of an intoxication.