Why would large doses of vitamin B2 less harmful than large doses of vitamin A?

Large doses of vitamin B2 (riboflavin) are generally considered less harmful than large doses of vitamin A because B2 is water-soluble, allowing excess amounts to be excreted through urine rather than accumulating in the body. In contrast, vitamin A is fat-soluble, which means it can build up to toxic levels in the liver and other tissues, leading to potential toxicity. While excessive intake of any vitamin can have adverse effects, the risk of toxicity is significantly higher with fat-soluble vitamins like A compared to water-soluble ones like B2.