Vitamin C and Immunity

What do humans and guinea pigs have in common? For both mammals, Vitamin C is an essential nutrient in their diets to maintain good health. Human and guinea pigs lack the enzyme that converts glucose, our blood sugar, to ascorbic acid, the chemical name for Vitamin C.  

The first human controlled clinical nutrition study was performed by Physician James Lind in May of 1747. He studied sailors who took long sea voyages and developed scurvy. Today we know that Scurvy is a disease that results from Vitamin C deficiency. Its symptoms include swollen, bleeding gums, loose teeth, easy skin bruising. Bruising is particularly seen around hair follicles. The hairs are brittle, corkscrew in shape and easily break off at the level of the skin. Later, in the course of Scurvy, patients develop profound fatigue, anemia, severe bone pain, particularly in the legs, poor wound healing and eventual death. Doctor Lind compared sailors given oranges and lemons to those who were not provided citrus fruits in their diet. Those who ate oranges and lemons were cured of scurvy compared to sailors not provided with these fruits. Almost 200 years passed, in the 1930s, before Hungarian scientist Albert Szent-Györgyi discovered the chemical ascorbic acid, today generally known as Vitamin C. He derived the Vitamin C from paprika, the national spice of Hungary. When this ascorbic acid was fed to Vitamin C deficient guinea pigs their signs of scurvy resolved. 

Not only is Vitamin C a powerful anti-oxidant but it is also boosts our immune responses to diseases. As an anti-oxidant in the skin, Vitamin C neutralizes and removes dangerous oxidants from our skin. Oxidants are naturally produced by our body and the environment, and if not cleared, damage our body’s proteins such as DNA and our essentials lipids. An overabundance of oxidants can thus cause disease and inflammation in the body. An anti-oxidant such as Vitamin C defends us against these oxidants.

Vitamin C also supports the barrier function of the skin preventing the invasion of dangerous bacteria. This is done by supporting the development of the basement membrane, the zone between the epidermis, the upper layer of the skin, and the second deeper layer of the skin, known as the dermis.

Vitamin C also supports the barrier function of the skin preventing the invasion of dangerous bacteria. This is done by supporting the development of the basement membrane, the zone between the epidermis, the upper layer of the skin, and the second deeper layer of the skin, known as the dermis. Vitamin C also helps the epidermal cells differentiate or progress in a normal fashion to enhance their barrier function. Vitamin C also is needed for the skin to produce barrier lipids which are also necessary for barrier function. These natural fats in the skin act as mortar between the epidermal cells which act as bricks. This epidermis wall is our first defense against invading bacteria. The dermis is largely composed of collagen, and Vitamin C is essential for collagen production. As an added benefit, as chronic sun damage and time leads to less collagen and damaged collagen in the skin, Vitamin C is not only important to prevent the entrance of dangerous invaders but it also has an anti-aging or wrinkle prevention effect on the skin.

In addition, on a cellular level, vitamin C is present in blood circulating, infection fighting white blood cells called neutrophils. Neutrophils chemically sense invading pathogens, engulf them;, kill them thus minimizing the risk of their multiplication leading to infections. Neutrophils also release chemicals that promote other neutrophils to come into the area of infection to help the cause. Another type of immune white cell, the lymphocyte also needs Vitamin C to differentiate or mature into cells that can actually produce antibodies or other cells that signal the immune system of the type of invading organism.

As result, deficiency of Vitamin C in the diet results in an impaired immune system and greater susceptibility to infections. In addition, infections decrease the Vitamin C levels in the body from increased inflammation generated by the infection. Also there is an increased requirement for Vitamin C during an infection due to increased metabolism needed to fight off infections

While the majority of people know that citrus fruits such as oranges lemons and tangerines contain higher doses of vitamin C, there are a few natural foods that actually are higher in Vitamin C based on weight. These include Kakadu plums, Acerola Cherries. Rose Hips  and Chilli Peppers. Other to consider include Guavas, Sweet Yellow Peppers, Blackcurrants, Parsley, Mustard Spinach, Kale, Kiwis, Broccoli, Brussels Sprouts, American Persimmons, Papayas, and Strawberries. Remember that the Vitamin C content is highest if these are eaten raw. Boiling drastically decreases the Vitamin C content. Steaming retains 90% of the Vitamin C content. If you do steam cook, then consider herbs and spices that are high in Vitamin C such as paprika mentioned above or fresh thyme. Others with high Vitamin C content include dill weed, saffron, pepper, red or cayenne, bay leaf, allspice, sage, and tumeric.