According to a review by Cochrane of 30 randomized trials involving more than 11,000 adults, for the general population, supplementation with vitamin C doesn't reduce the incidence of colds or upper respiratory tract infections in most adults.
However, for people under extreme stress, or who don't consume an adequate amount of fruits and vegetables, supplementation does appear to offer some protective benefits, and lower their risk of colds.
Regardless, the review found that once cold symptoms show up, taking a therapeutic dose of vitamin C will not affect the duration or severity of the common cold. (Note that companies like Airborne, which sell therapeutic doses of vitamin C, have been successfully sued for false advertising, and no longer use claims that they can prevent or cure common colds.)
Since colds are caused by viruses, antibiotics, which fight bacteria, won't help either.
Instead, turn to these natural remedies to shorten the length or severity of colds and flu:
Zinc is an essential mineral that plays an important role in immunity. Those who avoid meat, in particular, can be at risk for a zinc deficiency. The recommended daily intake (RDI) is 15 mg/day.
Studies show that adequate zinc consumption, or supplementation, not only prevents the onset of colds and flu, but also decrease the duration of them by a day or more, if taken at the onset of symptoms. Zinc is presently believed to be the most effective remedy against the common cold.
Some foods that contain zinc are oysters, crab, pumpkin seeds, sesame seeds, sunflower seeds, pine nuts, cashews, black beans, and shiitake mushrooms.
2. Elderberry Extract
Black elderberry juice can inhibit the growth of influenza viruses and shorten the duration of symptoms, while enhancing antibody levels against the virus. It helps reduce swelling in the sinuses and reduce congestion.
Elderberry can be taken as a liquid, syrup or tincture, as well as a lozenge and in capsule form.
Studies have found that fresh ginger effectively fights respiratory viruses. The same results were not found in powdered form, so use ginger in cooking or teas.
If you're looking for a good way to boost your nutrient intake this winter, try this Almond Ginger Monkey Smoothie. You can also prepare a simple tea by pouring boiling water over a few slices of fresh ginger and allowing to steep for at least 10 minutes.