You probably already know about the importance of vitamin C in boosting or supporting a healthy immune system, but you may be surprised to learn that there are several studies suggesting it may also be useful in helping us cope with stress, as well as being a natural antihistamine.

Many nutrients affect both mental health and the immune system, and it is now well-known that the central nervous system and immune system are intimately linked. The immune system plays a role in regulating feeding behavior, sleep, body temperature, and brain activity. Recently, studies have also shown a link between the incidence of depression with patients who suffer from allergies. Also, children with severe asthma have shown significantly more behavioral problems than those without asthma. Specifically, children with early onset asthma, before the age of four, tend to exhibit fearfulness, insomnia, and depressed mood.

The small molecule histamine is the body’s response mechanism to allergens and inflammation, and it is the over-production of histamine resulting from an allergic reaction or inflammation that causes many of the symptoms associated with common allergies, such as sneezing, runny nose or dry, itchy eyes. Histamine is also a neurotransmitter, linking the immune system and the central nervous system. Several studies have now linked the production of histamine in response to allergens or inflammation with increased anxiety levels, and it has also been linked with behavioral depression and Attention Deficit Disorder (ADD). This linkage may be due, in part, to the fact that histamine can activate the hypothalamic-pituitary-adrenal axis, one of our natural regulators for the “fight or flight” response to stress – which, when over-stimulated, can lead to depression. While there are a number of synthetic or pharmaceutical antihistamines available such as pseudoephedrine, diphenhydramine or doxylamine, the method by which they reduce histamine’s impact to our systems is by blocking molecular receptors – meaning, they prevent our body from allowing histamine to chemically bond with specific components of our immune and nervous systems. This process of receptor blocking can lead to several well-known side effects, such as drowsiness or excitability, especially in adolescents and children. Vitamin C, however, has proven itself to be a very potent and safe natural alternative. Vitamin C acts as an antihistamine by breaking down the small histamine molecule, rather than by blocking receptors – as a result, vitamin C does not have any of the adverse side-effects commonly experienced with pharmaceutical antihistamines. There are a number of other ways in which vitamin C supports our immune systems and promotes proper brain function. Besides being a powerful antioxidant, there is much evidence showing vitamin C as an important neuromodulator. Mood can be enhanced with vitamin C, and its positive role in mental health is illustrated by its potential to reduce anxiety when large doses are used, as well as possessing a mild antidepressant effect. Secretion of the hormone oxytocin is increased by vitamin C supplementation, naturally heightening our senses of arousal and well-being. Conversely, vitamin C deficiency consistently produces behavioral abnormalities and fatigue, in addition to the classic skin lesions seen in scurvy, a sickness that was often suffered by seafaring sailors, whose rations did not typically include sufficient fruits and vegetables.

Interestingly, many animals can synthesize vitamin C, creating the molecule naturally in their bodies – but humans (along with primates, guinea pigs, and some bats & birds) cannot. As a result, we need to ensure that we get sufficient amounts of vitamin C in our diet, from foods such as fruits (especially citrus, kiwi and berries) and many vegetables (such as red bell peppers broccoli, and dark leafy greens like spinach or kale). This is especially true as we grow older – studies have shown that as we age, our ability to maintain suitable vitamin C levels in our blood and tissues decreases. It’s important to note here that if vitamin C is taken as a supplement, we should also include calcium, magnesium, and bioflavinoids in our supplementation regimen, to ensure that our bodies can properly assimilate the vitamin. When taken naturally as with fruit or vegetables, these minerals will typically be naturally occurring.

While there is much debate on what the proper amount of vitamin C is, the USRDA of 60 to 90 mg per day for adults is much lower than many naturopaths and holistic health practitioners would recommend. For example, Dr. Linus Pauling, a two-time Nobel Prize winner, suggests that adult humans should be consuming as much as two to nine grams per day. The term megadosing in nutrition generally refers to taking at least ten times the recommended daily allowance (RDA) of a certain vitamin or mineral. Megadosing with vitamin C therefore is assumed to mean an adult supplementing with at least 600 mg/day of this vitamin. Calcium ascorbate, sodium ascorbate, and ester-C are better tolerated than ascorbic acid; presumably due to their non-acidic chemistry (ascorbic acid sometimes irritates the stomach). This may be especially helpful if someone is megadosing vitamin C.

It should be noted that there may be some risk in megadosing with vitamin C. For example, in some people it may produce kidney stones, and could result in intestinal gas. Also, megadoses of vitamin C may increase estrogen levels if contraception is being taken at the same time, and may cause a false positive diabetes test result. Some people reported experiencing dry nose, small skin cracks in the nasal passages and nosebleeds when supplementing with 2000 mg/day of vitamin C, which may increase the chance of infection. However, these side effects appear to be uncommon, and overall the vitamin appears to be very safe when taken in large quantities.

Author's Bio: 

Richard Jensen is a holistic health counselor and holistic nutritionist who has lived in San Diego since 1985. He received a Bachelor of Science in Microbiology and a Master of Science degree in Molecular Biology from San Diego State University. He has participated in various biochemical research projects, including HIV vaccine and cancer research. Richard then decided he wanted to help people more directly as a holistic health counselor and holistic nutritionist, receiving a Ph.D. in Holistic Nutrition from Clayton College, and has received a Nutritional Consultant Certificate (C.N.C.) from the American Association of Nutritional Consultants (AANC). He is currently practicing as a Holistic Health Counselor and Nutritional Consultant with an office in San Diego. Richard is available to provide personalized, custom-tailored nutrition programs that can be designed to address specific concerns, or to foster general improvements in health and wellness to positively impact the quality of life of his clients.