9 common nutrient deficiencies in the U.S.

You might not be getting enough of these vitamins from your diet

By Zoey Larsen | Updated on Dec. 22, 2022 Medically reviewed by Lindsey Hudson, APRN, NP-C, CDCES

Although most of us are aware of the benefits of eating a balanced diet, many people in the U.S. have nutrient deficiencies. In fact, more than 40% of Americans are deficient in Vitamin D, 7% are deficient in Vitamin C, and nearly 13% are deficient in vitamin B6. Failing to get key nutrients can lead to a variety of health problems, including fatigue, night blindness, osteoporosis, high blood pressure, and even acne.

If you’re experiencing the above symptoms and have ruled out other health conditions, you may suffer from a nutrient deficiency. Preventing and detecting the most common ones—including calcium, essential fatty acids, folic acid, iron, magnesium, and vitamins A, B12, C, and D—can be achieved through monitoring and adjusting your diet, considering dietary supplements and having a conversation with your healthcare provider if you suspect you have a vitamin or mineral deficiency.

What is a nutrient deficiency, and how do I know if I have one?

“A nutrient deficiency occurs when a body doesn’t get the necessary amount of nutrients it needs (a nutrient being a substance that is essential for growth, development, or the maintenance of life),” says Michael Jay Nusbaum, MD, the medical and surgical director at Nusbaum Medical Centers in New Jersey.

Many people have vitamin deficiencies but never realize it. Those who maintain a poor diet, eat poor quality food, or fail to take supplements are most at risk. In many cases, symptoms lead to a patient getting testing, which reveals the deficiency.

Once a nutritional deficiency is detected, it’s treated by providing the nutrients needed in the diet either through food, supplements, or both. In some severe deficiency cases, IV infusions may be necessary to replenish what is missing, according to Dr. Nusbaum.

9 common nutrient deficiencies

In the U.S., calcium, essential fatty acids, folic acid, iron, magnesium, and vitamins A, B12, C, and D are some of the most common nutrient deficiencies.

1. Calcium

Calcium’s main reputation comes from being an important building block for strong bones. But the essential mineral is also key for nerve and muscle function and heart health. Because calcium is stored in the bones and withdrawn when we don’t consume enough, a calcium deficiency leaves bones weak and more likely to break.

Nearly 70% of Americans fail to meet the recommended daily intake for calcium, which is due to either inadequate intake of calcium-rich foods or to poor absorption. Additionally, caffeinated beverages, alcohol, soda, dark leafy greens, beans and whole grains can decrease the body’s absorption of calcium. Signs of a calcium deficiency include mottled teeth, weak fingernails, or a numbness/tingling in the fingers or muscle cramps.

2. Essential fatty acids

“Essential fatty acid deficiencies occur when omega-3 consumption is too low, but symptoms can also appear if omega-6 fatty acid intake from processed foods is too high,” says Paul Kriegler, RD, the nutritional products program manager at Life Time. Symptoms include scaly skin, brittle or cracking nails and acne.

3. Folic acid

Folic acid, one of the many B vitamins, plays a role in maintaining healthy red blood cells and is particularly important during pregnancy, as women with low folic acid stores have a greater chance of having a baby with a neural tube defect (such as spina bifida). Outside of pregnancy, folic acid helps prevent anemia and heart disease.

Those who don’t consume enough fruits and vegetables (or who overcook their veggies) are at the greatest risk of developing a folate deficiency. People who consume high amounts of alcohol or who take certain medications (such as phenytoin, methotrexate, sulfasalazine, triamterene, trimethoprim-sulfamethoxazole, and barbiturates) have an increased risk of developing a folic acid deficiency. Symptoms may be similar to those caused by an iron deficiency, including fatigue, lethargy, hair loss, and shortness of breath

4. Iron

“Iron deficiencies can occur multiple ways: inadequate consumption of iron-rich foods, poor iron absorption, or iron loss through excess blood loss or during developmental stages in life such as adolescence, pregnancy or breastfeeding,” Kriegler says. Other people who have an increased risk of developing an iron deficiency include those with certain stomach or intestinal conditions that either cause bleeding or reduce the absorption of iron from food.

Iron deficiency anemia can cause general fatigue, headaches, dizziness, shortness of breath, muscle weakness, pale skin color and chest pain. In pregnant women, iron levels should be routinely checked, as expectant mothers are at an increased risk of developing this condition.

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5. Magnesium

Magnesium is an essential mineral that affects hundreds of metabolic reactions within the body, including regulating muscle and nerve function. “Many Americans don’t consistently consume adequate amounts of magnesium and most multivitamin supplements contain insufficient amounts of magnesium because it’s a bulky mineral that takes up a large volume of space in the formula, so it’s often recommended as an additional, stand-alone supplement,” notes Kriegler. Symptoms of a magnesium deficiency include muscle cramps, abnormal heart rhythms, unexplained numbness or tingling, and high blood pressure.

6. Vitamin A

Vitamin A is essential in the replacement of skin cells and for maintaining optimal vision and a healthy immune system. For this reason, those with a vitamin A deficiency are at an increased risk of acquiring a severe infection. As children are prone to infections, it’s crucial that those under the age of 5 get enough vitamin A in their diets or through supplements. In adults, one of the key warning signs of a vitamin A deficiency is night blindness.

7. Vitamin B12

One of the eight types of B vitamins, vitamin B12 helps to form red blood cells, enhances neurological function, and provides building blocks for DNA. Those most at risk for a vitamin B12 deficiency are vegans, people with intestinal problems that limit vitamin absorption, older adults, and those taking long-term heartburn medication. Symptoms of vitamin B12 deficiency are similar to those of anemia, including weakness, pale skin, shortness of breath, and mood changes.

8. Vitamin C

Vitamin C acts as an antioxidant within the body, helping to prevent damage inflicted by free radicals. Vitamin C also helps in hormone and amino acid formation; it also helps with the absorption of iron. The most commonly known effect of a vitamin C deficiency is scurvy, a fatal-if-untreated disease that causes inflamed and bleeding gums, easy bruising, weakness, fatigue, rashes, and difficulty healing wounds. While scurvy is uncommon today, proper vitamin C intake is still crucial for optimal health, as vitamin C regulates collagen production.

9. Vitamin D

Vitamin D is unique in that most vitamin D can be produced in our bodies when exposed to adequate amounts of UVB radiation from sunlight. Vitamin D’s key role is to regulate calcium absorption. Those with a vitamin D deficiency are unable to absorb that calcium and in turn strengthen bones. However, vitamin D has several other important roles for overall health, including supporting bone health, cardiovascular health, testosterone, and immune function.

Try to get 10-15 minutes of mid-day sun exposure of the face, hands, and arms without protective sunscreen may be enough to maintain healthy vitamin D levels, depending on the time of year, latitude, and skin pigmentation characteristics. Remember, if your skin is starting to turn pink, you’ve gotten too much sun.

How to prevent nutrient deficiencies

“The simplest way to prevent nutrient deficiencies is to eat a wholesome, nutrient-dense diet based on an abundance of produce (seven-plus servings per day) and ample protein, plus supplementing your diet every day with a high quality multivitamin, vitamin D, and omega-3 fish oil,” says Kriegler. If you’re concerned about a nutrient deficiency, there are a few steps you can take:

Get tested

Your healthcare provider can order a blood test to evaluate your essential nutrient levels if you’re exhibiting symptoms of a deficiency. An individual blood test can be conducted to assess a specific nutrient deficiency. However, a comprehensive nutrition panel is the most effective way to measure your overall health according to levels of vitamins, nutrients, and enzymes. Overnight fasting may be recommended to enhance the accuracy of results.

Evaluate your diet

Getting nutrients from your diet while avoiding processed foods, fast foods, and sugars is the ideal way to avoid a nutrient deficiency. Food sources include:

Calcium: Dairy products (milk, yogurt, or cheese), sardines, calcium-fortified orange juice, and dark green leafy vegetables
Folic acid: Eggs, leafy green vegetables, fruits, and dried beans and peas
Essential fatty acids: Cold water fish, flaxseed, and olive oil
Iron: Fortified dairy products, fatty fish, egg yolks, red meat, poultry, fish, and beans or legumes
Magnesium: Pumpkin seeds, leafy green vegetables, beans, legumes, and whole grains
Vitamin A: Spinach, chard, sweet potatoes, squash, pumpkins, carrots, mangoes, papayas, eggs and milk
Vitamin B12: Meat, fish, poultry, eggs, and dairy products
Vitamin C: Citrus fruits, broccoli, cantaloupe, cauliflower, kiwi, sweet potatoes, tomatoes, kale, bell peppers, and strawberries
Vitamin D: Fatty fish, beef liver, egg yolks, or a number of fortified foods (however, it’s almost impossible to achieve optimal vitamin D levels solely through diet, notes Kriegler)

Consider supplements

Even with a healthy diet, it can be difficult to achieve an optimal balance of nutrients. Supplements containing essential nutrients are available either alone, or in multivitamin formulas; your healthcare provider or pharmacist can help you determine the right balance of supplements.