Nicolai is a human nutrition and agriculture specialist, focusing on biofortification programs and the impact of biofortified staple crops on human health. Nicolai has conducted several clinical trials with focus on mineral bioavailability from foods, the development of chronic diseases and the effect of iron on gut microbiota. He conducted multiple trials in Rwanda investigating iron bioavailability from biofortified beans, and multiple large-scale micronutrient surveys. He has also worked on projects assessing the consumption of fortified foods in Ghana and optimizing the regulatory monitoring system for salt iodization in Ethiopia. He has worked on various projects in Oman, Uzbekistan, Kuwait, Ethiopia, Ghana, Gambia, Kuwait, Rwanda, Sierra Leone and Switzerland. He is currently based in Zurich, Switzerland.