Supplements Flashcards
Vitamin A -
- (RDA [ug/d] = 900 (3000 IU) ♂ vs 700 (2300 IU) ♀)
- Fat soluble forms exhibit highest bioavailability
- Role in vision and cell growth/differentiation
- High dosing (15000 IU) for retinitis pigmentosa
- Deficiency: xerophthalmia
- Role in xanthophyll transport to the retina
- Vit A toxicity associated with papilledema
- Reported risk of cancer in (former) smokers and alcoholics taking high dose vitamin A
*
Vitamin C
- (RDA [mg/d] = 90 ♂ vs 75♀)
- Collagen synthesis, wound healing & capillary integrity
- May impair hepatic acetaminophen metabolism -> toxicity (high doses)
- Risk of blood thinning effects
Is Vitamin A fat or water soluble?
Fat soluble
Vitamin A deficiency relating to the eye
xerophthalmia (impared goblet cell function)
Vitamin A dosing for retinitis pigmentosa
1500 IU
(RDA [ug/d] = 900 (3000 IU) ♂ vs 700 (2300 IU) ♀)
What role does Vit A play in the eye
Role in xanthophyll transport to the retina
Vit A toxicity associated with
Papilledema
Reported risk of cancer in (former) smokers and alcoholics taking high dose vitamin A
Vitamin E
- Fat soluble vs water soluble acetate or succinate
- Deficiency: opthalmoplegia (palsy of extra ocular muscle)
- Platelet inhibition at high doses (>1000mg); hemorrhagic stroke
- Risk of prostate cancer; recommend adding 200 ug selenium
Deficiency of Vit E relating to the eye
Opthalmoplegia
Zinc
- (RDA [mg/d] = 11 ♂ vs 8 ♀)
- Supports antioxidant enzymes
- Decreased in macular degeneration
- Zinc deficiency mimics Vit A deficiency owing to Zn-dependent conversion of Retinol -> Retinal
Copper
- (RDA [ug/d] = 900)
- Important role in critical enzyme function
- Absorption is decreased by excessive Zn ingestion; Cu supplementation is required with concomitant Zn administration to prevent Cu-deficiency anemia
Carotenoids
Lutein and Zeaxanthin
- 2 of the 3 naturally occurring pigments found in the human retina giving it an orange/yellow color
- Antioxidants
- Anti-inflammatory
- Filter harmful blue and UVA light
- RDA is 5 mg lutein + 1 mg zeaxanthin (5:1)
- Reduce glare disability and discomfort
- Reduce photo-stress recovery times (regaining sight post bleach)
- Increase contrast sensitivity (e.g. enhance vision in foggy conditions)
- Increase chromatic contrast threshold (e.g. tennis ball visualization)
- Increase visual range
Where is Lutein, meso-zeaxanthin concentrated in the Macula
Lutein: In the periphery
Meso-zeaxanthin: In the fovea
Ratio of lutein to zeaxanthin and mesozeaxanthin
Lutein 50%, zeaxanthin 25% and mesozeaxanthin 25%
(relates to RDA)
With what can you measure the macular pigment optical density (MPOD) and why
Maculoscope
Reduced MPOD is a suggested risk factor for macular degeneration
Can Beta-carotine be used as a supplement for macular degeneration
Beta-carotene (a vitamin A precursor) supplements have been suggested to compete with lutein and zeaxanthin for macular pigmentation
Omega 3
Ω3 Fatty Acids (AI [mg/d] 1600 ♂ vs 1100♀)
- Anti-inflammatory
- Antioxidant
- Blood thinner- bleeding risk
- Cholesterol lowering effects are mixed
- Help with dry eyes
- Short chain ALA18C is plant-derived and has 5% bioavailability in humans
- Long chain EPA20C & DHA22C are found in eggs & cold-water oily fish
- Grass-fed animals have Ω6:Ω3 ratios of 2:1
- Grain-fed animals have Ω6:Ω3 ratios of 4:1
- Concerns of fish oil contamination w/ heavy metals are unfounded; metals bind to proteins
- Some fish however have been found with high levels of mercury and potentially other heavy metals
- Products treated by molecular distillation under vacuum offer the lowest risk of contamination by fat-soluble pollutants
Bioavailability by Formulation and Structure
- Triglyceride (glyceryl) esters > Fish Body Oil > Free Fatty Acid > Ethyl Esters
DHA>EPA>ALA
Ratio of Ω6 to Ω3
- Dietary Ω6 intake averages 11x that of omega-3; largely due to its over-abundance in most meats and some oils
- Ideal ratios should be between 1:1-1:4 suggesting that intake of Ω3 should exceed Ω6
- Acceptable intake level of Ω3 is 1600 mg/d men vs 1100 mg/d women
Risk factors for macular degeneration
- Smoking
- Ultraviolet light
- Poor Diet: High BMI and carbohydrate intake
- Light Eyes
- Aging
- Family history: 50% lifetime risk of morbidity exists for patients with an affected relative vs a 12% to those without affected relatives
- Ethnicity: Caucasian > African Americans
- Macular drusen
- Co-morbidities: HTN
Basic formulation of macular degeneration suplements
Vitamin C 500 mg
Vitamin E 400 IU
Zinc 80 mg (zinc oxide) (or 25mg according to newer studies)
Copper 2 mg (cupric oxide)
Lutein 10 mg
Zeaxanthin 2 mg
Sources of AMD supplements
Vitamin B
- B vitamins (6, 9 and 12) are known to lower homocysteine protein levels, reducing inflammation
- Early studies suggest that B vitamins can lower the risk of developing macular degeneration
- Riboflavin (B2) is a potent antioxidant that is associated with a reduced risk of cataracts
- Niacin (B3) is a key vitamin cofactor of mitochondrial metabolic pathways and a powerful antioxidant associated with reduced risks of glaucoma
- Thiamine (B1) also plays a role in mitochondrial activity and is associated with reduced risks of cataracts and diabetic retinopathy
Which B vitamin is associated with a reduced risk for cataracts
B2 riboflavin
Ginkgo Biloba effects on open angle glaucoma
- Some literature refers to the neuroprotective role of Ginkgo Biloba thru its ability to improve cerebral blood flow
- Mitochondrial antioxidant
- Risk of blood thinning effects, hyphema, retinal hemorrhage
Marijuana effects on open angle glaucoma
• IOP lowering effects have never been proven to be therapeutically viable
Which antioxidant supplements are thought to reduce age related cataract progression
- Vitamin A
- Vitamin C
- Vitamin E
- Vitamin B Complex
- Omega 3 fatty acids § Lutein & Zeaxanthin
What supplement can be used to treat KERATOCONUS (KC)
- 1 in 500-2000 of people develop KC
- Characterized by corneal ectasia, KC is often diagnosed in adolescence
- As KC advances, vision diminishes, and the use of specialty contact lenses is a common non-surgical option
- Studies show that cross-linking between cornea collagen fibrils increases with age due to oxidative reactions
- In patients with diabetes, these oxidative reactions are also known to be enhanced, rendering them less susceptible to KC
- Once patients reach an age of 40-50 years, their cornea is 35 thought to have undergone its maximum crosslinking potential
- In April 2016, the FDA approved corneal crosslinking with Vit B2 and UV light for progressive KC, and 3 months later the procedure was approved for corneal ectasia
- Topical application of Photrexa® (Avedro Inc) to the eye is done after removing (epi-off) the epithelium
- The eye is then exposed to KXL® UVA light for up to 30 min leading to the production of ROS
- Covalent cross-links formed between amino terminals of the collagen side chains as well as to proteoglycans of the extracellular matrix provide enhanced mechanical strength and long lasting stabilization1
- Corneal thickness must exceed 400um in order to avoid endo damage
What supplements can be used for retinitis pigmentosa
As a degenerative, hereditary eye disease, the onset of RP sight deterioration can vary from one affected individual to the next
Vitamin A
• 15,000 IU of Vitamin A taken by adults with early or mid-stage RP
• Intracranial hypertension is linked to large doses of retinoids used inbtreatment of acne, psoriasis or to induce leukemia remission
Bilberry Fruit
• It has been suggested that pilots in WWII consumed bilberry jam to enhance night vision
Which supplements can be used against dry eye
Ω3 Fatty Acids
- Particularly useful in the most susceptible population
- AAO and AOA recommend Ω3 fatty acid for healthy tear film production
- Triglyceride (glyceryl) esters > Fish Body Oil > Free Fatty Acid > Ethyl Esters
- DHA>EPA>ALA
Vitamin A
• Vitamin A deficiency can result in xerosis of the conjunctiva and cornea, and alopecia of the eyelashes
Which antioxidants can be used against diabetic retinopathy
Bilberry fruit
- Properties linked to tannin content
Resveratrol
- Acts as an agonist of PPAR gamma, a nuclear receptor targeted in some DM-2 therapeutics
Vitamin B1 (Thiamin)
- A 2009 clinical study linked vitamin B1 supplementation to a reduction in albuminuria which is ai indication of diabetic retinopathy in Type 2 Diabetes
Vitamin D
- Deficiency is more common in non-insulin dependent diabetics and is lowest in those with diabetic retinopathy
Lutein & Zeaxanthin
