Fill a large pot with water and place it over high heat. Bring to a rolling boil and salt it generously.

Add the elbow macaroni to the pot and cook for about 10 minutes, or until slightly softer than al dente.

Carefully drain the pasta in a colander and immediately rinse under cold water. Set aside and let cool completely.

In a large mixing bowl, combine mayonnaise, white vinegar, granulated sugar, and whole milk. Whisk until smooth and creamy.

Add the cooled pasta, shredded carrots, and flaked tuna to the bowl with the dressing. Gently stir until evenly coated.

Cover the bowl tightly with cling wrap and refrigerate for at least 30 minutes, ideally overnight.