A major concern of taking excessive doses of vitamin C is the fact that large amounts of vitamin C can block copper absorption. Copper serves various functions in the body including production of the antioxidant, anti-inflammatory and immune stimulating enzyme copper superoxide dismutase. Copper is essential for the formation of collagen and elastin, which gives strength and elasticity to tissues. Copper also plays a role in the formation of neurotransmitters needed for proper nerve function. As a factor in the production of melanin, copper helps to prevent graying of the hair. In addition, copper helps to maintain proper levels of blood lipids (fats) including cholesterol.
Decreased copper levels can lead to decreased collagen and elastin synthesis. This in turn leads to bone loss, blood vessel weakness, poor wound healing, gum disorders, tendon and ligament weakness, cartilage disorders, bruising and wrinkles. Disorders such as emphysema and diverticulitis also involve loss of elastin in tissues.
The risk of heart disease increases with copper deficiencies. This is most likely due to weaker arterial walls combined with increased inflammation, increased oxidative damage and elevated cholesterol levels.
Vitamin C is often touted as an immune stimulant although excessive levels may have the opposite effect. The enzyme copper superoxide dismutase (cu-SOD) produces hydrogen peroxide in response to infections. Hydrogen peroxide serves various functions including activation of the immune system’s white blood cells. White blood cells fight infections and cancer cells within the body. Therefore, declining levels of cu-SOD can have an adverse effect on the immune system.
Inflammation has been shown to be a major contributor to the formation of cancers. Another primary function of cu-SOD is to reduce inflammation. Copper therefore may play a crucial role in other inflammatory diseases as well such as colitis and arthritis.
As an antioxidant, cu-SOD helps protect cells from free radical damage. The body requires free radicals such as hydrogen peroxide. Excessive levels of free radicals have been implicated in various diseases though, including cancer.
Hemoglobin requires copper for its production. Therefore, copper deficiencies can lead to anemia.
Copper is essential for the formation of thyroid hormones. Copper deficiencies lead to hypothyroidism, although excessive levels suppress thyroid function. This is especially true if zinc deficiencies are present since zinc promotes thyroid function. Note that excessive levels of zinc can over stimulate the thyroid.
As a cofactor in neurotransmitter production copper deficiencies can lead to depression. High copper levels though have also been linked to depression as well as schizophrenia, ADHD symptoms and other neurological disorders.
The brain and spinal cord contain some of the highest levels of copper in the body. Copper is not only essential for the formation of neurotransmitters but also for myelin, which insulates nerves so they do not “short circuit”.
Interestingly, the brain contains about 10 times the level of vitamin C as found in the blood. Vitamin C actually has to be oxidized to cross the blood-brain barrier. Oxidation converts the vitamin C in to dehydroascorbic acid, which allows it to be transported in to the brain through sugar receptors. There the dehydroascorbic acid is converted back in to ascorbic acid, commonly known as vitamin C. Here the vitamin C helps prevent damage to the myelin from free radicals and aids in the conversion of dopamine to norepinephrine.
Copper is essential for the proper regulation of histamine throughout the body. High levels of histamine can lead to allergic responses including asthma. In the brain histamine plays roles in mood, behavior, libido, addictions as well as sleep and wake cycles.
Despite all the benefits of copper, excess levels of copper can be dangerous. Copper supplementation is not recommended in most cases and if supplmented it should be combined with zinc. The common ratio of zinc to copper in supplements is 50mg zinc to 2mg copper. Women with excessive levels of estrogen would probably benefit more by taking zinc but not copper. Estrogen increases copper levels and zinc antagonizes copper helping to reduce the risk of copper toxicity.