What are fat-soluble vitamins, and why can they accumulate to toxic levels?

• A. Vitamins A, D, E, and K; because they dissolve in water and are readily excreted.
• B. Vitamins B-complex and vitamin C; because they dissolve in water and are excreted in urine.
• C. Vitamins A, D, E, and K; because they dissolve in fat and are stored in tissues.
• D. Vitamin C only; because it is water-soluble.

Answer: (C)

Fat-soluble vitamins dissolve in fats and are stored in the body's tissues, especially in the liver and adipose tissue. Because they’re stored rather than excreted quickly, they don’t need to be consumed every day, but they can build up to toxic levels if intake is consistently high, particularly from supplements. Absorption relies on dietary fat and bile, and once absorbed they travel with fats in the bloodstream and are retained in the body longer, making excessive long-term intake more likely to cause toxicity. The ones that fall into this group are A, D, E, and K.