Can Vitamin C help prevent COVID-19?

Vitamin C has lately been of interest to researchers in the fight against the COVID-19 pandemic. Large doses of intravenous Vitamin C are being tried in COVID-19 critical patients on ventilators in China.
Australian researchers reported that they did not find any benefit in using Vitamin C. But the U.S. is planning to try a combination of Vitamin C, Vitamin D, Zinc and hydroxychloroquine for COVID-19 prevention.
There is still no evidence to prove consuming a high amount of vitamin C is effective against coronavirus. According to Chennai-based Nephrologist Dr. Rajan Ravichandran, caution is required in consuming mega doses of vitamins without prescriptions, especially for long periods.
Vitamin C or Ascorbic acid is a water-soluble essential nutrient. Being water-soluble, it is not stored in the body and requires daily intake.
It is a powerful antioxidant with an important role in controlling infections and promoting healing of wounds. Its many functions include synthesis of collagen, chemical messengers in the brain and hormones.
The source of Vitamin C is fruits and vegetables like oranges and lemons. After consumption, the absorbed Vitamin C is metabolised in the body to oxalate and is removed by the kidneys. 
Large doses of Vitamin C have been used to improve the immunity and promote wound healing. Normally the body can cope with this high dose by reducing the absorption and increasing the oxalate loss in urine. But in some people, the oxalate can get deposited in the kidneys resulting in kidney failure. This is likely in patients with intestinal disorders and pre-existing kidney disease.
The daily requirement of Vitamin C is 90mg in adult males, 75mg for females which increases to 120 mg during pregnancy. 
Deficiency of Vitamin C is rare and but when it occurs, it is called scurvy. The deficiency can manifest with bleeding gums, delayed wound healing, skin spots, hair loss and anaemia.

Видео Can Vitamin C help prevent COVID-19? канала The Hindu