Multiple choice Which of the following is not a source of vitamin A? Carrot Mango Apple Yeast Grape Reveal answer Fill a bubble to check yourself D Correct answer Explanation Yeast is not a source of vitamin A. Nutritional yeast is a good source of protein, magnesium, copper and manganese and a very good source of dietary fibre, thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid and zinc.