7 Common Nutrient Deficiencies: Know the Signs

The hidden cause of common symptoms such as fatigue and muscle aches could be nutrient deficiencies. Are you at risk?

By Elizabeth Shimer Bowers

Medically reviewed by Farrokh Sohrabi, MD

You might think nutrient deficiencies are a thing of the past, reserved for sailors trapped at sea. But even today, it’s possible to lack some of the essential nutrients your body needs to function optimally.
“Nutrient deficiencies alter bodily functions and processes at the most basic cellular level,” says Tricia L. Psota, PhD, RDN, president-elect of the DC Metro Area Dietetic Association. “These processes include water balance, enzyme function, nerve signaling, digestion, and metabolism. Resolving these deficiencies is important for optimal growth, development, and function.”
Nutrient deficiencies can also lead to other diseases. “For example, calcium and vitamin D deficiencies can cause osteopenia or osteoporosis, two conditions marked by brittle bones,” says Kate Patton, MEd, RD, a registered dietitian at the Cleveland Clinic in Ohio. “And inadequate iron can cause anemia, which zaps your energy.”
Telltale symptoms are usually the first clue that you might be low in one or more important vitamins or minerals, says Patton. Here's how to recognize seven common nutrient deficiencies:
1. Calcium
Calcium is important for maintaining strong bones and controlling muscle and nerve function. Signs of severely low calcium include fatigue, muscle cramps, abnormal heart rhythms, and a poor appetite, Patton says. Make sure you're getting enough with at least three servings of milk or yogurt a day, she says. Other good sources of calcium are cheese, calcium-fortified orange juice, and dark, leafy greens.
2. Vitamin D
This vitamin is also critical for bone health. Symptoms of a vitamin D deficiency can be vague — fatigue and muscle aches or weakness. “If it goes on long term, a vitamin D deficiency can lead to softening of the bones,” Psota says.
To get enough vitamin D, Patton suggests having three servings of fortified milk or yogurt daily eating fatty fish, such as salmon or tuna, twice a week; and spending some time outside in the sunshine every day.
3. Potassium
Potassium helps the kidneys, heart, and other organs work properly. You could become low in potassium in the short term because of diarrhea or vomiting, excessive sweating, or antibiotics, or because of chronic conditions such as eating disorders and kidney disease, according to the U.S. National Library of Medicine. Symptoms of a deficiency include weight loss, muscle weakness, constipation, and in severe cases, an abnormal heart rhythm.
For natural potassium sources, Psota recommends bananas, whole grains, milk, vegetables, beans, and peas.
4. Iron
Iron helps your body make red blood cells. When iron levels get too low, your body can’t effectively carry oxygen. The resulting anemia can cause fatigue. You might also notice pale skin and dull, thin, sparse hair, Patton says. To boost iron levels, she recommends eating iron-fortified cereal, beef, oysters, beans (especially white beans, chickpeas, and kidney beans), lentils, and spinach.
5. Vitamin B12
Vitamin B12 aids the production of DNA and helps make neurotransmitters in the brain, says Rebecca Solomon, RD, director of clinical nutrition at Mount Sinai Beth Israel in New York City. With an increasing number of vegans and people who've had weight loss surgery, vitamin B12 deficiency is becoming more common, according to Harvard Health Publications. The organization says symptoms of severe B12 deficiency include numbness in the legs, hands, or feet; problems with walking and balance; anemia; fatigue; weakness; a swollen, inflamed tongue; memory loss; paranoia; and hallucinations.
You can get vitamin B12 from animal sources. “Boost your levels of B12 by eating more fish, chicken, milk, and yogurt,” Patton says. If you’re vegan, opt for vegan foods fortified with B12, such as non-dairy milk, meat substitutes, and breakfast cereals.
6. Folate
Folate, or folic acid, is a particularly important vitamin for women of childbearing age, which is why prenatal vitamins contain such a hefty dose. A folate deficiency can cause a decrease in the total number of cells and large red blood cells as well as neural tube defects in an unborn child, Psota says. Symptoms of a folate deficiency include fatigue, gray hair, mouth ulcers, poor growth, and a swollen tongue.
The Institute of Medicine’s Food and Nutrition Board recommends that women who could become pregnant take a folic acid supplement daily. To get folate from food, go for fortified cereals, beans, lentils, leafy greens, and oranges, Psota says.
7. Magnesium
Magnesium helps support bone health and assists in energy production. Although deficiency is fairly uncommon in otherwise healthy people, it can affect those who take certain medications, have certain health conditions, or consume too much alcohol, according to the National Institutes of Health’s Office of Dietary Supplements.
Magnesium deficiency can cause loss of appetite, nausea and vomiting, fatigue, and weakness. In more severe cases, it can lead to numbness, muscle cramps, seizures, abnormal heart rhythms, personality changes, or low potassium or calcium levels.
To help your levels return to normal, eat more magnesium-rich foods, such as almonds, cashews, peanuts, spinach, black beans, and edamame, Patton says.
From Nutrient Deficiency to Healthy Eating
If you suspect you have a nutrient deficiency, talk to your doctor. “Blood tests can help determine if you are deficient,” Patton says. And if you are, your doctor may refer you to a registered dietitian or recommend supplements.
The best way to avoid or remedy nutrient deficiencies is to make sure you are eating a balanced, nutrient-rich diet, Patton adds. “I encourage food first, but if you are at an increased risk of a nutrient deficiency, you may benefit from taking a multivitamin,” she says. And those at risk include vegans and those who are lactose-intolerant.