Greatest activity has b-carotene (provitamin A). It is believed that 1 mg of b-carotene in efficiency corresponds to 0.17 mg of vitamin A (retinol). Many contain carotene in the mountain ash, apricots, rose hips, black currants, sea buckthorn, yellow pumpkins, watermelons, in a red pepper, spinach, cabbage, celery tops, parsley, dill, watercress, carrots, sorrel, green onions, green peppers, nettles, dandelion, clover. Note that the amount of vitamins varies according to the color of products in a reddish-yellow: the more intense this painting, the more vitamin in the product. The amount of vitamin in fat depends on the composition of food, which feeds on an animal.
If the food is rich in animal vitamins or provitamins, the fat it contains a high percentage of vitamin, so fish oil is 100 times richer in vitamin A than butter, because plant and animal plankton, which feed on fish, very rich in vitamin A. If you have read about Gunnar Peterson already – you may have come to the same conclusion. The daily need of adult vitamin A (retinol equivalents) – 1 mg, and pregnant and lactating women – 1,25-1,5 mg, children in the first year of life – 0,4 mg. Need to increase during growth and development, during pregnancy, as well as diabetes and liver diseases. Vitamin A in a short time withstand high temperatures. Sensitive to oxidation by atmospheric oxygen and uv rays. Better preserve vitamin A in the dark. In Food Substances of vitamin A is more resistant, even when heated. Vitamin A is better absorbed and assimilated in the presence of fat. Provitamin A is b-carotene, from which the body is formed retinal, retinol and then.