Oil Fortification: Scientific Evidence
Global:Mandatory oil fortification legislation was first introduced in 1965. 27 countries have mandated oil fortification, since then. All 27 countries fortify with Vitamin A (range 6-55 mg/kg) and/or (range 0.075-1 mg/kg). Vitamin A is readily absorbed in the presence of oils and fats.
- After the introduction of vitamin A fortified margarine in Denmark at the end of 1917, the number of cases of xeropthalmia reported at a Copenhagen Hospital fell by more than 90% and by 1918 the condition had disappeared.Xeropthalmia is abnormal dryness of the conjunctiva and cornea of the eye, with inflammation and ridge formation, typically associated with vitamin A deficiency.
- Studies before and after the fortification of margarine in Newfoundland in 1944 report that the percent of subjects with serum vitamin A below 20 µg/dl declined from 48% to 2% over 4 years.
- More recently, a shelf stable margarine in the Philippines was fortified with vitamin A. After consuming the margarine for 6 months, the baseline prevalence of children with serum retinol levels below 20 µg/dl fell from 25.6% to 10.1%.
The biological value of vitamin A fortified oil has been reported in two studies. Dutra de Oliveira, et al. demonstrated that soybean oil with vitamin A in the form of retinal palmitate is well absorbed in humans given fortified oil along with a rice-based diet. Significant increases in plasma retinol were reported. Differences in plasma retinol for subjects receiving uncooked versus cooked soybean oil were not statistically significant. Favaro, et al report increased weight gain, plasma retinol and liver stores in rats consuming diets, which included fortified soybean oil.
India:Fortification of vanaspati with vitamin A has been obligatory in India since 1953. There is a government notification stating that no oil will be sold loose in the market, which is an advantage for the sale of packaged fortified oil. Government of Gujarat has made oil fortification mandatory in the state since 2006. 70-88 percent of vitamin A was recovered even after 30 days from open pails exposed to light and air at the Indian ports. During Indian cooking as well the levels have been found to be stable. When oil was added to mixture of rice, beans and pulses for Indian feeding programs, around 93 percent of vitamin A was retained after 15 minutes and 90 percent after 30 minutes of cooking. Even with deep frying pakoras in vanaspati at 200º C, retention ranged from 71% after 5 minutes, to 41% after 15 minutes .The stability of Vitamin D is found to be similar to that of vitamin A as little or no loss is reported during processing or storage.
(Vitamin A Fortification of P.L. 480 Vegetable Oil CONTRIBUTING AUTHORS Jack Bagriansky Peter Ranum PUBLICATION DATE 1998)