Benchmarking nutritional water productivity of twenty vegetables - A review

•Traditional vegetables are more nutrient dense in iron and zinc than alien vegetables.•β-carotene nutrient concentration of alien vegetables is higher than that of traditional vegetables.•Water productivity of traditional vegetables is comparable with that of alien vegetables.•Iron and zinc nutritional yields of traditional vegetables are higher than that of alien vegetables.•Alien vegetables are superior in β-carotene nutritional water productivity.