Rapid degradation of beta-carotene in the rice during storage and cooking means it's not a solution to vitamin A deficiency in the developing world. Report: Claire Robinson

The vitamin A precursor beta-carotene is only present at low levels in GM golden rice, when compared to carrots and green leafy vegetables. But it rapidly degrades to even lower levels when the rice is stored after harvest, a new study by Indian scientists has found. After just 6 months of storage in the presence of air, even at the low refrigerated temperature of 4 degrees C, the beta-carotene degraded by around 68–79%.

The lowest degradation rate was seen in paddy rice (unprocessed rice complete with the hull), the middle rate in brown rice (with the hull removed), and the highest in polished rice (with the hull removed and the bran mostly polished off). Polishing is the standard treatment given to rice throughout Asia. Brown rice is hardly ever eaten and paddy rice is never eaten.