Which of the following vitamins are most likely to build up to the point of toxicity with excessive intake?

• A. Vitamins A, C, E, K.
• B. Thiamin, riboflavin, niacin.
• C. Vitamins D, K, B₃ (niacin) & B₇ (biotin).
• D. Vitamins A, D, E, K.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the classification of vitamins. Vitamins are categorized into two groups: fat-soluble and water-soluble. Fat-soluble vitamins include A, D, E, and K, while water-soluble vitamins include the B-complex group (e.g., thiamin, riboflavin, niacin, biotin) and vitamin C.
2. Step 2: Recognize the storage and excretion differences between fat-soluble and water-soluble vitamins. Fat-soluble vitamins are stored in the liver and fatty tissues, making them more likely to accumulate to toxic levels with excessive intake. Water-soluble vitamins are generally excreted in urine, reducing the risk of toxicity.
3. Step 3: Analyze the options provided in the problem. Identify which vitamins are fat-soluble (A, D, E, K) and which are water-soluble (C, thiamin, riboflavin, niacin, biotin).
4. Step 4: Focus on the fat-soluble vitamins (A, D, E, K) as they are most likely to build up to toxic levels due to their storage in the body. Water-soluble vitamins (e.g., C, B-complex) are less likely to cause toxicity because they are not stored in significant amounts and are excreted readily.
5. Step 5: Conclude that the correct answer is Vitamins A, D, E, and K, as these are fat-soluble and prone to accumulation in the body with excessive intake.