Vitamin C: A Critical Component of Immune Health
Through mutation, humans lost the ability to endogenously produce vitamin C the way other mammals do, and we have to get it from dietary sources. But how much we really need on a daily basis to maintain optimal health, is still hotly debated. However, there is little debate that when it comes to optimizing immune function, there are a number of important reasons why supplementing with vitamin C can be beneficial. One important reason is that Vitamin C supports both the production and function of leukocytes (white blood cells), especially neutrophils, lymphocytes, and phagocytes.
Phagocytic leukocytes produce and release cytokines, including interferons, which have antiviral activity. Studies have reported that vitamin C supports the microbial killing capacities of neutrophils and supports the proliferation and differentiation of B- and T-lymphocytes which are of course, also responsible for destroying pathogens.
In response to invading microorganisms, phagocytic leukocytes release non-specific toxins, such as superoxide radicals, hypochlorous acid (“bleach”), and peroxynitrite; these reactive oxygen species kill pathogens and, in the process, can damage the leukocytes themselves. However, leukocytes accumulate vitamin C to high concentrations, which helps protect these cell types from oxidative damage. Vitamin C, through its antioxidant functions, has been shown to protect leukocytes from self-inflicted oxidative damage.
The amount of vitamin C a human needs daily has been the subject of controversy for many decades. But a scientific theory, called the dynamic flow model, which was published in 2005 in the Journal of Orthomolecular Medicine, explains all the observed responses to vitamin C in the literature. It refutes the current low dose hypothesis (that humans require only a few milligrams of vitamin C per day) and refutes the 200 mg saturation theory established by the NIH (which states tissue saturation occurs at 200 mg and taking more Vitamin C is pointless). It further states that when interpreted correctly, the NIH data actually supports high daily intakes.
According to the model, people should ideally be in a state of dynamic flow, which means they should ingest more vitamin C than they need, in the form of divided dose supplements throughout the day. The extra ascorbate flows through the body and is eventually excreted in the urine. Until then however, the excess acts as a reservoir when extra vitamin C is required. Dynamic flow suggests a way of restoring our physiology to the way it was before we lost the ability to make vitamin C in our bodies, as most other animals still do.
Experts in the field of integrative medicine emphasize the importance of supplementing vitamin C several times a day to ensure an adequate supply when needed for many different reasons, not the least of which is healthy immune system function.*
D.S. Hickey, Ph.D.; H.J. Roberts, Ph.D.; R.F. Cathcart, M.D. Dynamic Flow: A New Model for Ascorbate. Journal of Orthomolecular Medicine Vol. 20, No. 4, 2005