our SIGHT AND LIFE Newsletter 1/2006 included a paper on vitamin A fortification of edible oil as a cost-effective and sustain- able intervention program to sup- ply vitamin A to the population. It was good to know that vitamin A fortification of edible soybean oil was voluntarily implemented in Bangladesh: I hope the same will happen in other countries. In the 1990s our Brazilian nutrition group started to study and to put together scientific data to support the utilization of cooking oil as a vitamin A and carotene carrier to prevent vitamin A deficiency. One of the main obstacles for its use was the prestige of other vehicles like wheat flour and sugar, and the fact that vitamin A, being heat-sensitive, could not be added to a cooking ingredient. Our first published paper (1991) on the subject studied the stability of vitamin A added to refined soybean oil during cooking and storage. It was shown that, after 6 – 9 months of storing the oil in sealed metal cans at room temperature, the content of the vita- min A was still 99% of the original value. In open cans stored in a light environment the vitamin A content starts to decrease after 6 months. When the same fortified oil was used for the preparation of local rice and bean foods, boiling or under pressure, levels from 88% to 99% of the original vitamin A values were found. Levels of vitamin A in potatoes deep fried in vitamin A-fortified cooking oil at high temperature decreased slightly. Repeated frying of the same fortified oil at high temperature decreased the amount of vitamin A incorporated into the potatoes (1). Standard biological trials on vitamin A depleted rats fed non-fortified and A-fortified cooking oil con- firmed its bioavailability based on plasma and liver vitamin A levels (2). A final confirmation of the bio-utilization of the vitamin A fortified oil was obtained in normal human subjects by adding fortified oil to salad or to cooked food and measuring the post- absorption plasma peak rise and the area under the A-serum test curve. A control group receiving non-fortified oil did not show changes in comparison to their fasting plasma serum A levels, but the postprandial A plasma level increased threefold in sub- jects who received fortified oil (3). With these scientific studies we have provided a background of necessary scientific support for the use of cooking oil as a vitamin A carrier. Other similar studies were carried out with synthetic carotene also added to soybean oil. Rats receiv- ing diets with carotene-fortified soybean oil increased their liver vitamin A levels (4). Higher levels of plasma carotene were found when healthy adults received rice cooked with carotene-enriched soybean oil (5). We also advise mixing edible soybean and palm oil as a way to supply carotene. Although we did not explore this possibility further, it is certain to be effective. Anyway, our experimental and clinical studies sup- port vegetable oil as an effective vehicle to supply vitamin A or carotene to the relevant population. Unfortunately our studies have not received worldwide recognition. This is a rational and practical intervention and one of the best ways to supply people at community level with vita- min A and carotene. No special equipment is needed to add the vitamins – it is just adding oil to oil. The work in Bangladesh will certainly prove again that cooking oil has to be accepted and used as one of the most effective and practical low-cost carriers for the control of vitamin A deficiency. I hope other countries will follow it as a voluntary or compulsory way to guarantee the necessary intake of vitamin A everywhere.
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