Vitamin A Aids Night Vision in Deficient Adults

BRISBANE, AustraliaProviding vitamin A to patients awaiting liver transplant could enhance dark adaptation, according to results of a new study (Br J Ophthalmol. ePub 7 Aug 2010. DOI: 10.1136/bjo.2009.179176). Vitamin A deficiency is common in people with chronic liver disease, as the liver is the storage location of retinyl palmitate, which can be released to the body as needed. Such a deficiency is also common among adults with impaired dark adaptation, as a lack of retinol adversely affects the production of rhodopsin, a key pigment that supports the retinal rods ability to perceive light.

Researchers from Princess Alexandra Hospital developed a prospective study using 20 patients awaiting liver transplant who had low serum retinol levels, and 15 age-matched controls. Eight of the patients then received 50,000 IU of retinyl palmitate. Dark adaptation was measured with an SST-1 dark adaptometer and perception by questionnaire at baseline and again after one month.

At baseline, 40 percent of the patients had impaired dark adaptation, with greater incidence among the subjects with alcoholic liver disease. However, 75 percent of patients with impairment did not perceive a problem. After one month, the patients who received the intramuscular vitamin A could see light at half of the previous intensity, suggesting an improvement in dark adaptation.