The growing area of surgical treatment for obesity boosts the chances of vitamin A deficiency and results in vision loss, a medical journal has reported.
Researchers warn that ‘gastric banding’ and gastric bypass has helped bring about a rise of vitamin A deficiency in the developed world.
The small study, published ahead of print in the British Journal of Ophthalmology, was based on three patients with increasingly poor vision or night blindness, who attended a specialist eye clinic within the space of a year. None of the patients had a family or personal history of eye problems.
All three, who were all over the age of 65, had had extensive intestinal surgery between 20 and 35 years earlier and were diagnosed with vitamin A deficiency, in spite of them having taken vitamin supplements.
One of the patients refused injections of vitamin A into the muscles. But the other two went ahead with this treatment, which prompted an improvement in their vision within days.
Vitamin A is a fat soluble vitamin. It is absorbed through the small intestine as either retinol or carotene, and stored in the liver for up two years and transported to tissues as needed.
Vitamin A deficiency is the leading cause of childhood blindness in developing countries, and is caused by malnutrition. It is rare in affluent, developed countries, where it is mainly caused by poor absorption or abnormal metabolism.
Vitamin A is essential for the healthy working of the photosensitive pigment and superficial tissues of the eye. Night blindness is one of the most common symptoms of vitamin A deficiency.