Vitamins & Nutrition

The vitamins, minerals, and supplements used by the eye include vitamins A, B1, B2, B3, B5, B6, B12, C, D, E, K, zinc, copper, selenuim, lutein/zeaxanthin, bilberry, grape seed, magnesium, ginkgo biloba, lipoic acid, N-acetyl cysteine, quercitin, biotin, taurine, iron, folic acid, boron, calcium, chromium, iodine, manganese, molybdenum, choline, hesperidin, and omega-3 fatty acids http://ods.od.nih.gov/.   A well balanced diet will usually provide the necessary vitamins and minerals required by the eye.  The exception is with older people who may not be able to adequately absorb vitamin B12 or strict vegetarians who are not getting vitamin B12 because it is found only in animal-based foods.  Additional supplementation with fortified grain products or synthetic B12 is necessary with these individuals.  A diet high in fat and carbohtdrates has shown an increased risk for mild macular degeneration.  Certain eye conditions can however benefit from additional supplementation.  Some of these supplements are more important than others depending upon the particular disease.  For example, lutein + zeaxanthin decreases the risk of progression of macular degeneration by 10% to 26% depending upon  dietary intake (www.areds-2.com) and a daily supplement of 15,000 IU oral vitamin A, palmitate (not other forms of vitamin A) combined with an omega-3 rich fatty acid and 12 mg/day of lutein can slow vision loss in adults with the common forms of retinitis pigmentosa (Archives of Ophthalmologypublished online 13 Feb. 2012).   Omega-3 fatty acids are of benifit in dry eye conditions and vitamin C may help modulate the eyes intraocular pressure and decrease the risk of cataracts.

Caveat emptor - buyer beware.  Be informed  as you research what vitamins you choose to take.  Vitamin supplements can be the Wild West of American health for the uninformed.  There is debate between various vitamin studies and reports regarding whether supplementing with vitamins is important or necessary, there proper dosage, and what vitamins you should or should not take.  Be mindful of the risks associated with nutritional supplement ingredients.  Vitamins that may be beneficial for one condition may be contraindicated for another.    For example, hepatotoxicity has been observed in patients taking high levels of fat-soluble vitamins, such as vitamin A, particularly in those who abuse alcohol.  Forthermore, individuals with renal insufficiency must be cautious when taking high levels of water-soluble vitamins, such as vitamin C.  Zinc may be associated with Alzheimer disease, prostate cancer, copper deficiency anemia, genitourinary hospitalizations, and can inhibit the absorption of certain medications such as tetracycline.  Women who are pregnant or planning to become pregnant should not take high doses of vitamin A.  Vitamin E has been associated with increased heart failure risk.

The National Institutes of Health conducted a robust 4,203-patient clinical trial from 2006 to 2012 to evaluate the effects of various nutrients on eye health.  The study, called the Second Age-Related Disease Study (AREDS2) www.areds-2.com, was developed after an earlier study (AREDS) found age-related macular degeneration to be a nutrition responsive disorder reducing the risk of progression by 25%.  The AREDS/AREDS2 formulation was not found to be a cure for macular degeneration, nor was it found to be associated with vision restoration.  Long term use of AREDS supplements appears however to be safe and protective against advancement of macular degeneration.  A study published in the April 2013 issue ofOphthalmology by the AREDS Research Group showed that the benificial effects of taking the AREDS vitamins are long-lasting.  Vitamin A (beta carotene) was not included in the AREDS2 recommendations as it was in the original AREDS recommendations because more recent data has suggested that it may be associated with an increase risk of age-related maculopathy by suppressing the action of lutein and zeaxanthin and may increase the risk of lung cancer in smokers and prostate cancer.

The AREDS2 formulation and recommendations for macular degeneration include:

• Lutein (10 mg/day)
• Omega-3 essential fatty acids The AREDS 2 study determined that omega-3 had no benifit for macular degeneration as was assumed in the original study.  This finding is currently being questioned.  Omega-3 fish oil may be of benefit for other conditions such as: decreased triglyceride levels, which may affect atherlosclerotic plaque formation; lowered blood pressure; reduction in heart attack risk, stroke and dangerous abnormal heart rhythm in individuals with known heart disease; anti-inflammatory effect in rheumatoid arthritis; and a reduction in risk of breast and prostate cancers.  When choosing fish oil avoid fish liver oil because it has too much vitamin A.  Be aware that omega-3 supplements are highly variable in content.  A 1g capsule for example, might contain high levels of alpha-linolenic acid which is a shorter-chain omega-3 found in plant sources that must be converted into the longer forms of DHA and EPA to provide health/eye benifits.  A1000mg fish oil is a completely different supplement than a 1000mg "all natural" omega-3.
• Vitamin C (500 mg/day) Recommended diatery allowance is less, 90 mg/day for men and 75 mg/day for women.
• Zinc (80 mg/day) Recommended dietary allowance is less, 8 mg/day for women and 11 mg/day for men.  Toxicity level is between 100 to 300 mg/day.  Consumption greater than 50 mg/day may be associated with other health risks.
• Zeaxanthin (2 mg/day)
• Vitamin E (400 IU/day)   Recommended dietary allowance is less, 22.5 IU/day.  Achieving 400 IU/day through diet alone would probably put a person significantly over the daily recommendations for fat and calories, so supplementation would be indicated.
• Copper (2 mg/day)

Nutrition/Sources: 
First and foremost, important nutrients are best obtained through proper nutrition.  A healthy balanced diet, which includes fiber, fruits, vegetables, fish, and nuts, can be helpful in preventing the development or progression of macular degeneration.

• Lutein/Zeaxanthin:  Dark green leafy vegetables such as spinach, collards, or kale; corn, eggs.  Thedark green leafy vegetables also contain vitamin K which acts as a coagulant and may decrease the effects of anticoagulant blood thinners such as Coumadin and Warfarin.  Spinich also contains oxalic acid which can precipitate kidney stones which can be controlled by consuming magnesium.  Kale is the safer of the dark greens to consume.
• Omega-3 essential fatty acids (DHA/EPA):  Flax seed and walnuts (short-chain omega-3s) and/or free range deep water fleshy fish such as tuna or salmon (longer-chain omega-3s). 
• Vitamin A:  Whole eggs, milk, beef liver, fortified breakfast cereals, darkly colored fruits and vegetables (ie; carrots, cantaloupes, sweet potatoes, and spinach), and margarine.  Vitamin A in foods that come from plants is not as well absorbed as animal sources of vitamin A. 
• Vitamin C:  Orange juice, other citrus and fortified juices, and citrus fruits.  Multi-dose over time to increase absorption.
• Vitamin E:  Nuts, salad and vegetable oils, peanut butter, fortified cereals, and sweet potatoes.
• Zinc:  Red meat, poultry, oysters, fortified cereals, nuts, baked beans, and milk.  High doses of zinc may cause stomach upset and can interfere with cooper absorption.
• Copper:  Mixed nuts, sunflower seeds, and beans.
• Miscellaneous:  Green/black tea, grapes (particularly the seeds), blueberries, red wine.

Product Examples:
I-caps (AREDS formula lutein & zeaxanthin), Ocuvite Extra, Ocuvite PreserVision, Ocuvite Lutine, MaxiVision, Eye-Vite Plus (with lutein), and others. 

Additional Information:

• Lutein/Zeaxanthin:  Naturally occurring within the lens and retina/macula and functions to protect it from the adverse effects of peroxidation from blue/ultra violet light.  It is a critical ingredient to assist the retina/macula in the prevention of its destruction.  Taking lutein/zeaxanthin increases macular pigment density.   http://ods.od.nih.gov/pubs/elderly.14jan03.abst.chew.pdf#search="lutein"
• Omega-3 essential fatty acids:  Modulates the immune system.  Important in meibomian gland function and therefore helpful in treating dry eye conditions.  Controls inflammation of ocular surfaces.  Is normally occuring in the retina.  Omega-3 fatty acids may create gastrointestinal problems, acne, and prostate hypertrophy.  Acts as a blood thinner and therefore may be contraindicated in platelet abnormalities, anti-coagulation therapy, and high dose aspirin therapy.http://ods.od.nih.gov/Health_Information/omega_3_fatty_acids.aspx
• Vitamin A:  Vitamin A is a group of compounds that play an important role in vision, bone growth, reproduction, cell division, and cell differentiation.  Vitamin A helps regulate the immune system, may help lymphocytes fight infections more effectively, and promotes healthy surface linings of the eyes (retina) and the respiratory, urinary, and intestinal tracts.  Vitamin A also helps the skin and mucous membranes function as a barrier to bacteria and viruses. In general, there are two categories of vitamin A, depending on whether the food source is an animal or a plant. Vitamin A found in foods that come from animals is called preformed vitamin A.  Vitamin A that is found in colorful fruits and vegetables is called provitamin A carotenoid.  15,000 IU of oral vitamin A palmitate in combination with omega-3 fatty acids and lutein has been shown to slow the progress of retinitis pigmentosa which effects 1 in 4,000 people in the Unites States (1:1,878 in Navajo's) .  15,000 IU of vitamin A is only available from two sources; Freeda Vitamins (freedavitamins.com) and J.R. Carlson Laboratories (carlsonlabs.com). Vitamin A may increase the risk of lung cancer in smokers and should not be used by women who are pregnant or planning on becoming pregnant.  http://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
• Vitamin C:  Is an active antioxidant highly concentrated within the eye and assists with the antioxidant activity of vitamin E.  Is normally occuring in the cornea, lens, vitreous, and retina.  It works to remove harmful free radicals from the retina/macula and build collagen.  It may help lower the intraocular pressure and decrease the risk of cataract formation. In excess it may create gastrointestinal problems.http://ods.od.nih.gov/factsheets/VitaminC-QuickFacts/
• Vitamin E:  Protects the retina/macula as an antioxidant preventing the formation of rancid fats.  It works to remove harmful free radicals from the retinal/macular structures.  It protects the vascular system from plaque buildup.  In high doses it can cause hemorrhages and interfer with blood coagulation by inhibiting platelet aggregation so beware when used with Coumadin and other blood thinners.  Not recommended with Retinitis Pigmentosa. http://ods.od.nih.gov/factsheets/VitaminE-QuickFacts/
• Zinc:  This mineral is important in the formation of a number of crucial enzymes within the eye.  It helps to move vitamin A from the liver.  Can potentially increase serum lipids if dosed above 60 mg per day.  May not be recommended for those at risk for Alzheimers Disease. http://ods.od.nih.gov/factsheets/Zinc-QuickFacts/
• Copper:  It is important to supplement copper when taking zinc because zinc depletes copper concentrations within the body thus causing anemia.

NOTE:  Additional risk factors for macular degeneration include smoking (increases risk 2 1/2 times), older people, fair-skinned, light-eyed, high dietary polyunsaturated fat, elevated cholesterol, and ultra-violet light exposure. 

www.ocularnutritionatoz.com
www.aoa.org/nutrition.xml
www.nei.nih.gov/amd
http://ods.od.nih.gov/
http://www.ncbi.nlm.nih.gov/pubmedhealth/s/drugs_and_supplements/a/
www.areds-2.com
http://archopht.ama-assn.org/cgi/content/short/129/4/470