Vitamin C is used most often for preventing and treating the common cold. Some people use it for other infections including gum disease, acne and other skin infections, bronchitis, human immunodeficiency virus (HIV) disease, stomach ulcers caused by bacteria called Helicobacter pylori, tuberculosis, dysentery (an infection of the lower intestine), and skin infections that produce boils (furunculosis). It is also used for infections of the bladder and prostate.
Some people use vitamin C for depression, thinking problems, dementia, Alzheimer's disease, physical and mental stress, fatigue, and attention deficit-hyperactivity disorder (ADHD).
Other uses include increasing the absorption of iron from foods and correcting a protein imbalance in certain newborns (tyrosinemia).
There is some thought that vitamin C might help the heart and blood vessels. It is used for hardening of the arteries, preventing clots in veins and arteries, heart attack, stroke, high blood pressure, and high cholesterol. Vitamin C is also used for glaucoma, preventing cataracts, preventing gallbladder disease, dental cavities (caries), constipation, Lyme disease, boosting the immune system, heat stroke, hay fever, asthma, bronchitis, cystic fibrosis, infertility, diabetes, chronic fatigue syndrome (CFS), autism, collagen disorders, arthritis and bursitis, back pain and disc swelling, cancer, and osteoporosis.
There are circumstances when supplemental vitamin C would be helpful, namely any time the horse’s immune function is depressed when the additional antioxidant may give a needed boost to the system. As the demands increase on the body, producing stress, the body may not be able to synthesize sufficient vitamin C to keep up with the demand. Horses that work really hard, like endurance horses, eventers, and racehorses; horses in prolonged stressful situations (such as a long transportation or multiday competitions); postoperative and post-trauma horses; horses suffering from wounds, infections or diseases; arthritic horses; horses with heaves or allergies; and aged horses with chronic infections or decreased immunity may benefit from supplemental vitamin C