Which nutrientwhen deficient in the diet causes a lack of haemoglobin in red blood cells?

A deficiency of iron in the diet can lead to a lack of hemoglobin in red blood cells, resulting in iron-deficiency anemia. Hemoglobin requires iron for its synthesis, and without adequate iron, the body cannot produce enough healthy red blood cells to effectively transport oxygen. This deficiency can lead to symptoms such as fatigue, weakness, and pale skin.