Recently a paper titled, Perspective: Improving vitamin D status in the management of COVID-19 was published in the European Journal of Clinical Nutrition (2020).
When a chemical reaction to a cholesterol-based molecule takes place and converts it into calcidiol in the liver and into calcitriol in the kidney due to fall of sunlight on the skin, vitamin D is produced.
Vitamin D is associated with infections in the respiratory tract and lung injury and also help prevent osteoporosis
Vitamins A, D, E, and K are fat-soluble.
Fat-soluble vitamins are absorbed along with fats in the diet and can be stored in the body’s fatty tissue.
They come from plant and animal foods or dietary supplements.