Why should consumers be cautious about megadoses of fat-soluble vitamins in OTC products?

• A. They can accumulate in the body and cause toxicity with excessive intake
• B. They are water-soluble and easily excreted in urine
• C. They have no interactions with medications
• D. They are always safe at high doses

Answer: (A)

Megadoses of fat-soluble vitamins pose a toxicity risk because these vitamins are stored in the body's fat tissues and liver and are not readily eliminated. When taken in excess, the surplus can build up over time, leading to hypervitaminosis with effects that vary by vitamin (for example, excessive vitamin A can affect vision and liver, while too much vitamin D can raise calcium to dangerous levels). Because they persist in the body, stopping the supplement doesn’t quickly reduce levels, so the harm can accumulate with continued high intake. In contrast, water-soluble vitamins are more readily excreted in urine, which is why they’re less likely to accumulate. It’s also not true that fat-soluble vitamins are always safe at high doses, and they can interact with medications and certain health conditions, so cautious use and adherence to recommended amounts are important.