Avoid Vitamin A (2016) for Stargardt's
Learn more about complementary treatment for Stargardt's disease.
For most vision conditions vitamin A plays an important and necessary role. This article discusses how vitamin A plays opposing roles in Stargardt's disease, where it should be avoided, and retinitis pigmentosa, where it is helpful.
Usually vitamin A helps to increase macular pigmentation increasing protection to the retina. But in Stargardt's patients it increases the rate of toxic waste accumulation because vitamin A cannot be properly metabolized. In these patients the nutrient lutein also increases pigmentation in the retina but does not cause vision degradation.
The researchers evaluated the dietary habits and consumption of vitamin A in 24 patients with Stargardt's and retinitis pigmentosa. The patients were evaulated using standardized testing procedures that indicate either condition. In both groups the age that symptoms of the condition appeared were taken into consideration as indicators of the severity of the condition - where the condition appears at a younger age it is more severe.
The researchers looked at eating habits involving 109 foods over a yearly period as opposed to seasonal or a few weeks' eating habits. They asked how often the patients ate each of the listed foods - whether daily, weekly, monthly, etc.
Comparing recommended dietary intakes to food consumption of these patients diets they found that both groups consumed more total fat, less from polyunsaturated fats, low levels of fiber, high levels of cholesterol, and low levels of some minerals and vitamins -- particularly calcium, potassium, magnesium, vitamin D, B6, and folic acid.
Over 58% of the Stargardt's patients consumed more vitamin A than recommended for that condition, with one patient consuming so much vitamin A as to be considered toxic. That patient had especially poor vision. The 6 patients who consumed very low levels of vitamin A had much better visual acuity.
The RP patients with high levels of vitamin A had later onset of the condition.
Intake of fatty acids was also evaluated. Both patient groups, RP and Stargardt's had diets with insufficient EPA and DHA.
The small sample size imposes some limitations in conclusions but these conclusions agree with animal and other studies investigating vitamin A intake in Stargardt's patients. Diets low in vitamin A and with sufficient other nutrients are recommended.
Researchers: Francesco Sofi, et al.
Published: Dietary profile of patients with Stargardt's disease and Retinitis Pigmentosa: is there a role for a nutritional approach? BMC Ophthalmology, January, 2016.