Vitamin A deficiency can lead to impaired vision, especially in dim light, due to its role in the production of rhodopsin, a protein essential for low-light vision.

Iron deficiency anemia can be caused by insufficient dietary iron, poor absorption of iron (e.g., due to certain medical conditions), or increased iron loss (e.g., through heavy menstrual bleeding).

Iodine deficiency is the primary cause of goiter, as iodine is essential for the production of thyroid hormones, which regulate metabolism and growth.

Vitamin B12 deficiency is primarily caused by poor absorption of the vitamin, often due to a lack of intrinsic factor, a protein produced by the stomach that aids in vitamin B12 absorption.

Niacin deficiency, also known as pellagra, can cause a range of symptoms, including dermatitis, diarrhea, and dementia, due to its role in various metabolic processes.

Vitamin D plays multiple roles in the body, including promoting calcium absorption, supporting immune function, and maintaining bone health.

Vitamin C deficiency, also known as scurvy, can cause various symptoms, including bleeding gums, skin problems, and impaired wound healing, due to its role in collagen synthesis.

Zinc deficiency can be caused by insufficient dietary zinc, poor absorption of zinc (e.g., due to certain medical conditions), or increased zinc loss (e.g., through diarrhea or excessive sweating).

Thiamin deficiency, also known as beriberi, can cause a range of symptoms, including neurological and cardiovascular problems, due to its role in energy metabolism.

Calcium plays multiple roles in the body, including supporting bone health, regulating muscle contractions, and maintaining nerve function.

Vitamin A deficiency can lead to night blindness, as it is essential for the production of rhodopsin, a protein necessary for low-light vision.

Iodine deficiency is primarily caused by insufficient dietary iodine intake, as the body cannot produce iodine on its own.

Anemia can be caused by deficiencies in iron, vitamin B12, or folic acid, as these nutrients are essential for the production of red blood cells.

Vitamin K's primary function is to promote blood clotting by helping to produce proteins involved in the coagulation process.

Rickets can be caused by deficiencies in vitamin D, calcium, or phosphorus, as these nutrients are essential for bone mineralization.