Too Much Vitamin C Increases Risk for Blindness
Vitamin C (ascorbic acid or ascorbate) is not only essential to health, it is also essential to survival. Larger amounts of vitamin C than is promulgated as the 60-mg Recommended Dietary Allowance (RDA) for vitamin C have been acknowledged by most of the members of the National Academy of Sciences committee that sets these standards as likely beneficial for optimum human vitamin C concentrations for support of our immune defense mechanisms.
Dr. Benjamin C. Lane, Director of the Nutritional Optometry Institute, reported in 1980 that the physiological effectiveness of vitamin C in reducing intraocular pressure——as is a concern in most glaucomas——is, with high probability, proportional to the logarithm of the concentration of the ascorbic acid. In other words, statistically speaking, to lower the intraocular pressure twice as much as 100 mg [=102 mg] of vitamin C can do, we would ordinarily have to go to approximately 104 mg of vitamin C [=10,000 mg]! On the other hand, it is amazing to note that 100 mg has fully half the effectiveness of the 10,000 mg of supplemental ascorbic acid, generally called vitamin C. Such a use of megavitamin therapy may or may not be justified. A nutritionally informed eye doctor needs to calibrate and monitor the effect and make the rather difficult judgment between likelihood of lowering intraocular pressure versus increasing the risk for other eye disorders.
The fact that humans are so excellently capable of clearing large doses of vitamin C is an important aspect of its chelating ability——its ability to pull out heavy metals from the body as it itself is cleared from the body. But ascorbic acid also chelates out desirable nutrients ——essential minerals such as copper and chromium——taken in at the same meal. Consequently, it does matter whether vitamin C is ingested before, during, or after a meal! “Bowel tolerance” is one criterion for administering ascorbic acid. But it is not necessarily a safe nor adequate criterion. Other risks need to be considered.
What possible hazards become present when we go to megadoses of vitamin C? The research at the Nutritional Optometry Institute has demonstrated that a major effect of megadosing of ascorbic acid (vitamin C) is the development of an increased risk or probability of developing greater liquefaction of the jelly-like substances inside the largest chamber of the eye——the vitreum (*commonly spelled “vitreous”). This liquefaction promotes the quite common and usually innocuous fibrillar degeneration of the vitreum, producing vitreous floaters. Unfortunately, the progressing liquefaction also increases the risk for vitreous detachment from the retina and subsequent retinal detachment and a third form of macular degeneration, variously called “macular pucker” and “cellophane maculopathy.” The retinal detachment as well as the macular degenerations can, but do not have to, lead to legal blindness. Specific tests are available to aid in assessing the risk.
More and more, eye doctors, optometrists and ophthalmologists, are learning how to counsel their patients as to prudent dietary behavior. When the prudent behavior utilizes natural, non-invasive methods with minimal expense and minimal hazard, it becomes prudent to recommend and monitor these strategies, at least for persons at imminent risk.
The Nutritional Optometry Institute has long been in the vanguard of dietary research and therapy in the prevention of eye disorders.
In one of our next articles, we’ll talk about the specific nutrients that are essential to prevent and reverse the most common of the eye and vision disorders, including the many species of cataracts, the macular degenerations, and the vitreous pathologies.
