Which of the following is not a micronutrient?
Iodine
Iron
Glucose
Boron
If the daily requirement is more than 100 mg, they are called major elements or macrominerals. If the requirement of ceain minerals is less than 100 mg/day, they are known as minor elements or microminerals or trace elements, micronutrients. Options A and B are micronutrients. Option D : Boron is still regarded as a possibly essential element with no proved significance. Reference : D M Vasudevan , 6th edition page 411
nutrition and digestion