A lower than normal amount of any vitamin or mineral in the body--whether caused by dietary deficiencies or digestive problems that interfere with proper nutrient absorption--can result in a number of medical conditions and problems. Insufficient amounts of Vitamin D and iron both cause a characteristic set of signs and symptoms. While some are similar, both conditions can result in a different set of medical problems.
Weakness and Fatigue
Deficiencies in both Vitamin D or iron can cause you to feel abnormally tired and to experience muscle weakness as well as unexplained muscle pain and aches. According to the National Institutes of Health, Vitamin D is an essential component of neuromuscular health and plays an important role in regulating the genes that code for the production of cell proliferation and differentiation. A decreased amount of Vitamin D in the body makes the work of muscles and muscle cells more difficult.
Muscles need oxygen to work properly, and a low amount of iron interferes with the amount of oxygen muscle cells receive. This is because iron is needed for the body to produce hemoglobin, the compound that allows red blood cells to transport oxygen to body tissues. Without enough iron, the red blood cells carry less oxygen, resulting in muscle weakness and tiredness.
Decreased Immune Function
A low amount of available iron in the body can cause you to suffer from repeated and persistent infections since the lack of iron prevents blood cells from functioning optimally. Likewise, Vitamin D is an essential component in proper immune regulation and the modulation of the inflammatory response. Without enough of either or both of these nutrients, the immune system cannot effectively deal with bacterial or viral invasions.
Vitamin D deficiency is directly linked to bone development and strength since it is one of the most important vitamins involved in the dietary absorption of calcium and phosphorous and the promotion of bone growth. Young children who suffer from low Vitamin D have a much higher risk of developing rickets, a condition characterized by weak, easily bent bones. Adults with a Vitamin D deficiency can develop osteoporosis which results in brittle bones prone to breaking. Low amounts of iron in the blood are not directly related to skeletal disorders in the same way that Vitamin D is.
Since iron is essential for the transportation of oxygen throughout the body, an insufficient amount of iron can cause you to suffer from shortness of breath and, because of the lack of oxygen, lightheadedness, dizziness and unusual headaches. Vitamin D deficiency is not normally associated with any types of respiratory difficulties.