Which of the following is NOT a water-soluble vitamin?

• A. Niacin (Vitamin B3)
• B. Vitamin A
• C. Thiamin (Vitamin B1)
• D. Vitamin C

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the classification of vitamins into water-soluble and fat-soluble categories. Water-soluble vitamins dissolve in water and are not stored in large amounts in the body, while fat-soluble vitamins dissolve in fat and can be stored in body tissues.
2. Step 2: Identify the vitamins listed in the problem: Niacin (Vitamin B3), Thiamin (Vitamin B1), Vitamin C, and Vitamin A.
3. Step 3: Recall that the B-complex vitamins (including Niacin and Thiamin) and Vitamin C are water-soluble vitamins. This means they dissolve in water and need to be consumed regularly.
4. Step 4: Recognize that Vitamin A is a fat-soluble vitamin, meaning it dissolves in fat and can be stored in the body's fatty tissues and liver.
5. Step 5: Conclude that since Vitamin A is fat-soluble and the others are water-soluble, Vitamin A is the correct answer as the vitamin that is NOT water-soluble.