Consider the following statements: 1. Caffeine, a constituent of tea and coffee is a diuretic. 2. Citric acid is used in soft drinks. 3. Ascorbic acid is essential for the formation of bones and teeth. 4. Citric acid is a good substitution for ascorbic acid in our nutrition. Which of the statements given above are correct?

1. Statement 1 is correct. Caffeine, found in tea and coffee, acts as a mild diuretic, increasing urine production. 2. Statement 2 is correct. Citric acid is commonly used as a flavoring agent and preservative in soft drinks. 3. Statement 3 is correct. Ascorbic acid (Vitamin C) is essential for collagen synthesis, which is crucial for the formation and maintenance of healthy bones and teeth. 4. Statement 4 is incorrect. While both are acids, Citric acid cannot replace ascorbic acid in nutrition because ascorbic acid has specific vitamin functions (like acting as an antioxidant and cofactor) that citric acid lacks. 5. Therefore, statements 1, 2, and 3 are correct.