What are signs of lack of nutrients?

Nutrition : Your question is too broad to answer sufficiently. There are too many nutrients and too many signs to review. Restate with specifics if you can.

Nutrient deficiency: Many signs of nutrient deficiencies occur. Depends on the nutrient. Protein malnutrition results in kwashiorkor; hypoglycemia can result from inadequate carbohydrates before vigorous, prolonged exercise. B12 deficiency can result in numbness and tingling of the extremities and dementia. Vitamin d deficiency can cause loss of height, bone fractures, fatigue, infections and cancers.