Deficiency of this vitamin, which is stored in the liver, can occur in alcoholics causing night blindness and poor immune function. However population-based studies in the UK and elsewhere reveal that heavy drinkers have higher levels of retinol in the blood and this is almost certainly due to the increased mobilisation of the vitamin from the liver compared with low consumers. Supplements can also be damaging to the liver and high intakes may increase the risk of fatty liver disease which is common in heavy, especially overweight drinkers. http://www.food.gov.uk/multimedia/pdfs/reviewvita.pdf page
It is thus prudent for all not to exceed the Safe Upper Level of 1500 ug per day, which typically means that any vitamin supplement should not provide more than 800 ug per daily dose. Heavy drinkers especially those with abnormal liver function tests or established alcohol-induced liver disease should not take any supplements of retinol without expert assessment advice.