A woman who has been following a vegan diet may need ____ supplements.

Correct Answer: B

Rationale: The correct answer is B: vitamin D and vitamin B12. Vegans may need to supplement vitamin D and B12 as these nutrients are mainly found in animal products. While choices A, C, and D are essential vitamins, they are not typically lacking in a vegan diet. Vitamin C can be obtained from various plant sources, vitamin A can be derived from beta-carotene in plants, and vitamin E and K are also found in plant-based foods. Niacin, although important, can be sourced from plant-based sources and is not a common deficiency in vegan diets.

Correct Answer: C

Rationale: The correct answer is C: Fats. A ketogenic diet is characterized by high fat intake, moderate protein intake, and very low carbohydrate intake. This diet aims to shift the body's metabolism to use fat as the primary source of energy instead of carbohydrates. Increasing fat intake while reducing carbohydrates is essential for achieving and maintaining a state of ketosis. Therefore, choices A, B, and D are incorrect as they do not align with the macronutrient adjustments required for a ketogenic diet.

Correct Answer: C

Rationale: The primary function of antioxidants in the diet is to neutralize free radicals. Free radicals can cause cellular damage, leading to various chronic diseases. Antioxidants help combat this oxidative stress by neutralizing free radicals. Choices A, B, and D are incorrect because antioxidants do not provide energy, support muscle growth, or increase blood sugar; their main role is in combating oxidative stress.

Correct Answer: C

Rationale: Vitamin K is vital for the synthesis of clotting factors, which are necessary for proper blood clotting. Vitamin A (Choice A) is important for vision and skin health, not blood clotting. Vitamin E (Choice B) is an antioxidant that helps protect cells from damage but is not directly involved in blood clotting. Vitamin C (Choice D) is essential for collagen synthesis and a healthy immune system, but it does not play a direct role in blood clotting.

Correct Answer: B

Rationale: The correct answer is Vitamin C. Vitamin C enhances the absorption of non-heme iron, which is crucial for patients with anemia. Vitamin A (Choice A) is not directly involved in iron absorption. Vitamin D (Choice C) helps with calcium absorption, not iron. Vitamin E (Choice D) does not have a significant role in iron absorption.