Animal fats, fish liver oils, milk, butter, eggs, liver , kidneys are a rich source of Vitamin A. Its provitamin form is called Beta carotene. Green and yellow parts of plants (spinach, drum sticks, spring onions, cabbage, pumpkin, carrots, tomato),yellow fruits like mango, papaya are a rich source of carotenes.
Its deficiency has many manifestations on the skin. It common in infants and young children. Extensive dryness is an early sign. In adults it is seen as thick small swellings at the openings of the hair. Most commonly it is seen over the outer side of arms and thighs. If the deficiency continues , it spreads to the shoulders, face, chest, abdomen, back and buttocks.
A dry, firm brown follicular swelling with is seen and on removal of the plug a pit is found. A severe form of this is seen as sharp spiny small swellings especially around the elbow areas in children and is called Phrynoderma meaning like this spiny thick skin of a Toad.
Studies say this kind of skin changes happen more with mixed deficiencies of vitamin A, E, B - complex, C and essential fatty acids.
Along with skin changes severe vitamin A deficiency causes blindness. It starts as night blindness, inability to see bright light, dry eyes, foamy white triangular patches in the eye, eventually dry eyes leading to ulcers in the eye, scarring and blindness.
The daily normal requirement in infants and children less than four years of age is 1500 IU of Vitamin A and 5000 IU in those older than 4 years. To prevent such medical conditions in developing countries like India 2 lakh IU is given every 6 months to pre-school children orally.
In those who already have the deficiency Vitamin A supplements are given as capsules or injections along with education about the dietary intake of the vitamin A rich food. It is also advisable to supplement other vitamins, minerals like zinc and essential fatty acids to correct the skin manifestations.