Compliance status and stability of vitamins and minerals in Fortified Maize Flour in Kenya

Fortification of staple foods is a cost-effective strategy that has been used to reduce the prevalence of micronutrient deficiency in the population. National mandatory maize flour fortification legislation was introduced in Kenya in 2012 to help address micronutrient deficiencies among the vulnerable groups of the population. This study aimed to quantify the amount of vitamin A, vitamin B2, B3, B9, iron and zinc in maize flour and premixes, relative to the national fortification standard, EAS 768 and determine the stability of micronutrients in fortified maize flour under normal storage conditions experienced in Kenya. A total of 27 maize flour brands and 2 brands of maize flour premixes were procured from the market and analyzed for compliance with the national standards for vitamin A, vitamin B2, vitamin B3, vitamin B9, iron, and zinc. Losses of micronutrients in fortified maize flour stored at 25°C/RH 60% and 35°C/RH 75% for six months were also quantified. Overall, the level of compliance of fortified maize flour to national standards was low with only 11.1% of the samples complying in the micronutrients analyzed. According to the Government of Kenya, compliance is accorded to brands that comply in at least three micronutrients. Only 48.1% of the samples had complied in three or more of the micronutrients analyzed. Compliance status for specific micronutrients to national standards varied greatly with minerals having higher compliance levels than vitamins. About a fifth (18%) of the samples from the market did not comply for any micronutrient analyzed. Some samples had folate and retinol levels below detectable limits. The retention of the vitamins analyzed was significantly affected by storage conditions (temperature and relative humidity). Low retention was observed for storage at 35°C/RH 75% compared to 25°C/RH 60%. In conclusion, fortification of maize flour is still low in Kenya and there is a need to strengthen efforts towards improved compliance.