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Still Ginned Up for Vitamin C

Friday, August 13, 2010


Discussions with one of my favorite ophthalmic researchers, Stuart Richer, OD, PhD, chief investigator of the Lutein, Antioxidant Supplement Trial (LAST), usually get me ginned up about a particular nutrient and its effect on the eye. 
 
Dr. Richer wrote his doctoral dissertation on Vitamin C. This gives him exceptional expertise on this subject so I listen carefully when he speaks about one of my most favorite vitamins.  
 
Linus Pauling wrote in the foreword of  Dettman, Kalokerinos, and Dettman Vitamin C is Nature's Miraculous Healing Missile, "The juice of lemons and oranges are antiscorbutics to be commended. And, without boasting, I can affirm that I have never observed in my whole practice so many happy effects by any one simple medicine as by lemons."
 
Unfortunately, humans do not have the ability to make their own vitamin C like most other mammals. Therefore, we must obtain vitamin C through our diet and from supplements.
 
Vitamin C is required for the synthesis of collagen, the structural component of blood vessels, tendons, ligaments, and bone. It plays an important role in the synthesis of the neurotransmitter norepinephrine, which is particularly critical to eye and brain function. It is also required for the synthesis of carnitine, the chemical molecule essential for the transport of fat to cellular organelles called mitochondria for conversion to energy.
                             
Mitochondria are responsible for producing the ATP energy required for cellular function, including in the retina. Mitochondrial diseases associated with the eyes include macular degeneration, retinitis pigmentosa, diabetic retinopathy, optic atrophy, cataracts, and drooping eyelids (ptosis).
 
I must mention that supplemental Vitamin C has also been suggested in a number of studies to have an inhibitory effect on carcinogenesis because of its free-radical scavenging activity against oxidative DNA damage.  It is suggested to control the transcription level expression of genotoxic metabolites that can lead to mutagenesis.
 

Vitamin C Recommended Daily Allowance (RDA)

Unfortunately, the vitamin C RDA continues to be based primarily on the prevention of deficiency diseases like scurvy, rather than the prevention of chronic degenerative diseases and the promotion of optimal health. The current vitamin C RDA is only 90 mg per day for males and 75 mg per day for females.

The Linus Pauling Institute at Oregon State University reports that most of the information regarding vitamin C and the prevention of chronic disease is based on prospective studies that assess vitamin C intake in large numbers of people who are followed over time to determine whether they develop specific chronic diseases.
 
We find it disturbing that data from the National Institutes of Health clearly indicates that plasma and circulating cells in healthy subjects require approximately 400 mg per day of supplemental vitamin C to reach cellular saturation associated with optimal health.
 

Vitamin C & Coronary Heart Disease

Results from the First National Health and Nutrition Examination Study (NHANES I) Epidemiologic Follow-up Study suggest that the risk of death from cardiovascular disease was 42% lower in men and 25% lower in women who consumed more than 50 mg per day of dietary vitamin C, and who regularly took vitamin C supplements, which equaled about 300 mg per day.

The Nurses Health Study, which followed more than 85,000 women for more than 16 years, also suggests a daily intake of more than 350 mg of vitamin C to be cardio-protective.

A recent pooled analysis of 9 prospective cohort studies, including more than 290,000 adults who were free of coronary heart disease at baseline and followed for an average of 10 years, found that those who took more than 700 mg/day of supplemental vitamin C had a 25% lower risk of coronary heart disease than those who did not take supplemental vitamin C.

This analysis makes one wonder why the Institute of Medicine has not increased the Vitamin C RDA for adults. The Institute of Medicine has set the safe upper limit for vitamin C supplementation at 2,000 mg per day, primarily to prevent adults from experiencing diarrhea and other gastrointestinal disturbances, which go away with the discontinuation or reduction of high-dose vitamin C supplementation.

Food Sources

The three highest food sources of vitamin C are:

Sweet red peppers (282 mg per one cup serving)
Strawberries (82 mg per one cup serving)
Orange juice (75 mg per one cup serving) 
 

Vitamin C Supplementation

Supplemental ascorbic acid vitamin C is inexpensive and available in many forms. Natural and synthetic L-abcorbic acid is chemically identical and there appears to be no difference in their biological activity or bioavailability.

Ascorbyl palmitate, on the other hand, is a vitamin C that has been esterified to palmitic acid, resulting in a longer-chain fat-soluble form of vitamin C with a longer half-life. Ascorbyl palmitate easily crosses cell membranes and protects fats from peroxidation. It works best when taken in combination with ascorbic acid.

Biosyntrx multiples, Oculair and Macula Complete, include 500 mg of vitamin C, as a mixture of ascorbic acid and ascorbyl palmitate.

Ellen Troyer, MT MA
Biosyntrx CEO /  Chief Research Officer

PEARL

Stuart Richer, OD, PhD,r will be one of the lecturers at the November 16, 2010 Ocular Nutrition Society all day CE course in San Francisco.  The informative and fun-filled six hour continuing education event is titled:

From Testing to Tasting: An Integrative Approach to Eye Health:

Bill Rafferty, OD, FAAO and Ann Hoscheit, OD, FAAO: Don’t Guess, Test. Dr. Rafferty is an Assistant Professor of Optometry at the Duke University Eye Center and an Adjunct assistant professor of Optometry at the University of Alabama.. Dr. Hoscheit is in private practice in Gastonia, North Carolina. Both Drs, Rafferty and Hoscheit are Board Certified in Anti-Aging and Functional Medicine (FAAFM).

Burton Goldberg, D Hum: How to See Disease Before it Manifests – The Quantum Physics Approach. Burton is the author/publisher of the big gray, Alternative Medicine: The Definitive Guide, which has sold over 750,000 copies. Burton has spent over 30 years researching every aspect of holistic medicine, including nutritional influence on health. He is frequently referred to as "The Voice of Alternative Medicine."

Stuart Richer, OD, PhD, FAAO: The Role of Cardiac Biomarkers in Ophthalmic Care. Dr. Richer is the Chief of Optometry at DVA Medical Center in Chicago, as well as an Associate Professor of Family and Preventative Medicine at Chicago Medical School. He is the chief investigator of the Lutein, Antioxidant, Supplement Trial (LAST) study.

Kimberly Reed, OD, FAAO: New Perspectives on Free Radicals, Antioxidants and Age Related Eye Disease. Dr. Reed is a Professor of Optometry oat Nova Southeastern University, School of Optometry. Her area of expertise is Pharmacology and Nutrition.

Paul Williams, PhD – "Exercise & Eye Disease" Dr. Williams is a very published researcher at Lawrence Livermore Labs in Berkeley, CA. His primary research has been on how subclasses of lipoproteins (the particles that transport nutrients in the blood) are affected by exercise, diet, drugs and other factors. He recently published studies on exercise and eye disease.

Karen MacNeil, MA –> "The Health Benefits of Good Food and Wine." Karen is a sought after lecturer and the author of the New York Times best selling book on wine called "The Wine Bible:" now in its 10 printing. Karen’s first book was Whole Foods: The Book of Nutrition & Cuisine. Karen will wrap up this CE day by conducting a wine tasting on three different red wines in keeping with the ONS "Cabernet, Chocolate and Chatter" tradition.

This lineup promises to entertain, as well as educate.

Crestpoint Management, LTD instrument announcement:
Mackool-Inamura Capsulorhexis Forceps with Blunt Tips 2-2-706-GR

References

Linus Pauling Institute - Oregon State University http://lpi.oregonstate.edu/infocenter/
 
Vitamin E and vitamin C supplement use and risk of all-cause and coronary heart disease mortality in older persons: the Established Populations for Epidemiologic Studies of the Elderly. Losonczy KG, Harris TB, Havlik RJ. Am J Clin Nutr. 1996;64(2):190-196. (PubMed)
 
Vitamin C and risk of coronary heart disease in women. Osganian SK, Stampfer MJ, Rimm E, et al. J Am Coll Cardiol. 2003;42(2):246-252. (PubMed)
 
Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts. Knekt P, Ritz J, Pereira MA, et al. Am J Clin Nutr. 2004;80(6):1508-1520. (PubMed)
 
Long-term ascorbic acid administration reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Gokce N, Keaney JF, Jr., Frei B, et al. Circulation. 1999;99(25):3234-3240. (PubMed)
 
Effects of vitamin C on hyperoxia-induced reduction of retinal blood flow. Weigert G, Luksch Am et al. Microvasc Res. 2009 May;77(3):256-9 [PubMed]