Answer to Question 1
In the prevention and treatment of the common cold: Vitamin C has been a popular option for the prevention and treatment of the common cold for decades, but research supporting such claims has been conflicting and controversial. Some studies find no relationship between vitamin C and the occurrence of the common cold, whereas others report modest benefitsfewer colds, fewer days, and shorter duration of severe symptoms, especially for those exposed to physical and environmental stresses. A review of the research on vitamin C in the treatment and prevention of the common cold reveals a slight, but consistent reduction in the duration of the common cold in favor of those taking a daily dose of at least 200 milligrams of vitamin C.
Discoveries about how vitamin C works in the body provide possible links between the vitamin and the common cold. Anyone who has ever had a cold knows the discomfort of a runny or stuffed-up nose. Nasal congestion develops in response to elevated blood histamine, and people commonly take antihistamines for relief. Like an antihistamine, vitamin C comes to the rescue and deactivates histamine.
Answer to Question 2
Although not defined as a vitamin, choline is an essential nutrient that is commonly grouped with the B vitamins. The body uses choline to make the neurotransmitter acetylcholine and the phospholipid lecithin. During fetal development, choline supports the structure and function of the brain and spinal cord, by supporting neural tube closure and enhancing learning performance.
Choline is found in a variety of common foods such as milk, eggs, and peanuts and as part of lecithin, a food additive commonly used as an emulsifying agent.