The body requires many different vitamins and minerals that are crucial for both body development and preventing disease. A nutritional deficiency occurs when the body does not absorb or get from food the necessary amount of nutrition. Deficiencies can lead to a variety of health problems which include digestion problems, skin disorders, stunted or defective bone growth, and even dementia. The most widespread nutritional deficiency worldwide is iron deficiency. Iron deficiency can lead to anemia. This is a blood disorder that causes fatigue, weakness, and a variety of other symptoms. When you are iron-deficient, your body produces fewer red blood cells. The red blood cells it produces are smaller and paler than healthy blood cells. They are also less efficient at delivering oxygen to your tissues and organs. Iron is found in foods such as dark leafy greens, red meat, and egg yolks. It helps your body make red blood cells.