Below threshold: Nutritionists discuss serious yet common mineral deficiencies
Monday, Feb. 13, 2017
MANHATTAN — Iron and zinc are critical minerals, but many people are deficient in them. The good news, according to nutritionists at Kansas State University, is that these deficiencies can be diagnosed through a simple blood test and are easily treatable.
Brian Lindshield, associate professor of food, nutrition, dietetics and health, says iron deficiency is especially common in menstruating and pregnant women because of blood loss and increased blood volume, respectively. Lindshield says the recommended daily allowance of iron is 18 milligrams per day for menstruating women and 27 milligrams per day for pregnant women. Men need only 8 milligrams per day.
Women need more iron because they lose more iron, says Linda Yarrow, instructor of food, nutrition, dietetics and health. An iron deficiency may be an extra concern for pregnant women who face hemodilution, in which increased body fluids dilute hemoglobin levels while increased mineral levels are needed for fetal growth.
"Given that an ounce of beef provides 1 milligram of iron, it can be a challenge for women of childbearing age to meet their iron needs through diet alone," Lindshield said.
Lindshield and Yarrow say the human body needs iron for proper enzyme function; oxygen transportation through the blood; and adequate growth, development and synthesis of some hormones. The nutritionists say iron deficiency can result in anemia, which causes symptoms of fatigue, weakness, lethargy, apathy, impaired cognitive abilities, decreased immune function and headaches.
While iron deficiency is somewhat common, Yarrow says it is rare for the deficiency to be found alone.
"Because iron deficiency can be related to poor diets and blood loss, persons with iron deficiency tend to have other nutrient deficiencies as well," Yarrow said.
Zinc, for example, is a mineral that is often found with iron. Beef, soy and whole grains all contain both iron and zinc. Similarly, where iron deficiency is found, zinc deficiency also is often present. Zinc deficiency is less common than iron deficiency, but it is more common than most other mineral deficiencies, Yarrow says.
Zinc deficiency is most likely in older adults, children living in food-insecure households, persons with alcoholism, and those with vegan diets, especially in developing countries. Lindshield says veganism can contribute to zinc deficiency because zinc is not absorbed as well from plant foods as from animal-based foods.
Zinc is required for cellular metabolism and is important for immune function, wound healing and DNA synthesis. The mineral also is necessary for adequate senses of taste and smell. Zinc deficiency can result in hair loss, dermatitis, growth retardation, loss of appetite, poor wound healing, and altered senses of taste and smell.
Yarrow advises anyone who suspects they may have deficiencies in iron, zinc or any other minerals to consult their physician rather than attempting to self-diagnose or self-treat. A physician will ask questions about dietary intake and symptoms and possibly order laboratory work to determine if any deficiencies are present, Yarrow says.
If deficiencies are confirmed, the client will receive education about increasing intake of foods that contain the deficient nutrient. The client also may receive recommendations on supplements to take to achieve desired nutrient levels. Yarrow says this process is crucial because there is plenty of misinformation on the internet and because if a supplement is needed, self-determining which supplement to take and how much can be harmful. For example, overly high levels of Vitamin D have been linked to health problems, Yarrow says.
"Nutrient deficiencies can be damaging, but excesses of many nutrients can be just as detrimental," Yarrow said. "Excessive intake of any nutrient has potential harmful effects, so please visit your physician for deficiency diagnosis and treatment."