ISSA Nutritionist Practice Exam

Cholesterol is needed in the synthesis of what vitamin?

1. Vitamin A

2. Vitamin C

3. Vitamin D

4. Vitamin E

The correct answer is: Vitamin D

Cholesterol plays a crucial role in the synthesis of Vitamin D. When the skin is exposed to sunlight, specifically UVB radiation, cholesterol undergoes a chemical transformation that ultimately leads to the production of Vitamin D. This process begins with the conversion of 7-dehydrocholesterol, a compound that is derived from cholesterol, into previtamin D3, which is then converted into active Vitamin D (calcitriol) through further metabolism in the liver and kidneys. Vitamin D is essential for various bodily functions, including the regulation of calcium and phosphorus levels, which are critical for maintaining healthy bones and teeth. Additionally, sufficient Vitamin D levels are also important for immune function and overall health. The other vitamins listed do not rely on cholesterol for their synthesis, thus highlighting the unique relationship between cholesterol and Vitamin D specifically.