Nutritional Deficiencies (Malnutrition)

What Are Nutritional Deficiencies?


  1. Nutritional deficiencies, known as malnutrition, are the result of your body not getting enough of the nutrients it needs.
  2. Children are more at risk for serious complications due to nutritional deficiencies than adults.
  3. You can prevent nutritional deficiencies by making sure you get enough nutrients from your diet. You should talk to your doctor and dietitian to help make any decisions on dietary changes and before taking any nutritional supplements.

The body requires many different vitamins and minerals that are crucial for both development and preventing disease. These vitamins and minerals are often referred to as micronutrients. They aren’t produced naturally in the body, so you have to get them from your diet.

A nutritional deficiency occurs when the body doesn’t absorb the necessary amount of a nutrient. Deficiencies can lead to a variety of health problems. These can include problems of digestion, skin problems, stunted or defective bone growth, and even dementia.

The amount of each nutrient you should consume depends on your age. In the United States, many foods that you buy in the grocery store (such as cereals, bread, and milk) are fortified with nutrients that are necessary to prevent nutritional deficiency. But sometimes your body is unable to absorb certain nutrients even if you are consuming them.

Keep reading to learn about some common nutritional deficiencies and how to avoid them.

Types of Nutritional Deficiency

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It’s possible to be deficient in any of the nutrients that your body needs. Some common types of nutritional deficiencies include:

Iron Deficiency

The most widespread nutritional deficiency worldwide is iron deficiency. Iron deficiency can lead to anemia, a blood disorder that causes fatigue, weakness, and a variety of other symptoms

Iron is found in foods such as dark leafy greens, red meat, and egg yolks. It helps your body make red blood cells. When you’re iron deficient, your body produces fewer red blood cells. The red blood cells it produces are smaller and paler than healthy blood cells. They’re also less efficient at delivering oxygen to your tissues and organs.

According to the World Health Organization (WHO), over 30 percent of the world’s population suffers from this condition. In fact, it’s the only nutritional deficiency that is prevalent in both developing and industrialized countries. Iron-deficiency anemia affects so many people that it’s now widely recognized as a public health epidemic.

Vitamin A Deficiency

Vitamin A is a group of nutrients that is crucial for eye health and functioning and reproductive health in men and women. It also plays a part in strengthening the immune system against infections. According to the WHO, a lack of vitamin A is the leading cause of preventable blindness in children. Pregnant women who are deficient in vitamin A have higher maternal mortality rates as well.

For newborn babies, the best source of vitamin A is breast milk. For everyone else, it’s important to eat plenty of foods that are high in vitamin A. These include:

  • milk
  • eggs
  • green vegetables, such as kale, broccoli, and spinach
  • orange vegetables like carrots, sweet potatoes, and pumpkin
  • reddish yellow fruits, like apricots, papaya, and peaches

Vitamin B-1 (Thiamine) Deficiency

Another common nutritional deficiency occurs with vitamin B-1, also known as thiamine. Thiamine is an important part of your nervous system. It also helps your body turn carbohydrates into energy as part of your metabolism.

A lack of thiamine can result in weight loss and fatigue, as well as some cognitive symptoms such as confusion and short-term memory loss. Thiamine deficiency can also lead to nerve and muscle damage and can affect the heart. In the United States, thiamine deficiency is most often seen in those who chronically abuse alcohol. Alcohol reduces the absorption of thiamine, the body’s ability to store thiamine in the liver and the body’s ability to convert thiamine to a usable form. Thiamine deficiency is a common cause of Wernicke-Korsakoff syndrome.

Many breakfast cereals and grain products in the United States are fortified with thiamine. Pork is also a good source of the vitamin.

Vitamin B-3 (Niacin) Deficiency

Vitamin B-3 (niacin) is another mineral that helps the body convert food into energy. A severe deficiency of niacin is often referred to as pellagra. Niacin is found in most proteins. As a result, this condition is rare in meat eating communities. Symptoms of pellagra include diarrhea, dementia, and skin problems. You can usually treat it with a balanced diet and vitamin B-3 supplements.

Vitamin B-9 (Folate) Deficiency

Vitamin B-9, often referred to as folate (folic acid is the synthetic form found in supplements or fortified foods), helps the body create red blood cells and produce DNA. It also helps brain development and nervous system functioning.

Folate is especially important for fetal development. It plays a crucial role in the formation of a developing child’s brain and spinal cord. Folate deficiency can lead to severe birth defects, growth problems, or anemia.

You can find folate in foods, including:

  • beans and lentils
  • citrus fruits
  • leafy green vegetables
  • asparagus
  • meats such as poultry and pork
  • shellfish
  • fortified grain products

Most people in the United States get enough folate. But pregnant women and women of childbearing age sometimes don’t consume enough folate for a healthy pregnancy. The National Institutes of Health (NIH) recommend that women who are pregnant or who may become pregnant consume up to 400 mg of folate or folic acid each day to help prevent birth defects.

Vitamin D Deficiency

According to the Vitamin D Council, about 40 percent of the population worldwide is affected by vitamin D deficiency. Dark skinned individuals are at a higher risk of vitamin D deficiency.

Vitamin D is essential for healthy bones. It helps the body maintain the right levels of calcium in order to regulate the development of teeth and bones. A lack of this nutrient can lead to stunted or defective bone growth. Osteoporosis, caused by a lack of calcium and vitamin D, can lead to porous and fragile bones that break very easily.

Vitamin D is found naturally in only a few foods. Foods with vitamin D include:

  • fish liver oils
  • fatty fish
  • mushrooms
  • egg yolks
  • liver

Many dairy products in the United States are fortified with vitamin D. Ultraviolet light from the sun is also a source of vitamin D. According to the NIH’s Office of Dietary Supplements, research suggests that five to 30 minutes of sun exposure twice a week on the face, arms, neck, or back can provide you with enough vitamin D. (Although recommended for UV protection, sunscreen does hinder vitamin D absorption from sunlight through the skin, so spend a few minutes in the sun prior to sunscreen for optimal vitamin D absorption).

Calcium Deficiency

Calcium helps your body develop strong bones and teeth. It also helps your heart, nerves, and muscles work they way they should. A calcium deficiency often doesn’t show symptoms right away, but it can lead to serious health problems over time. If you aren’t consuming enough calcium, your body will use the calcium from your bones instead, leading to bone loss.

Calcium deficiencies are related to low bone mass, weakening of bones due to osteoporosis, convulsions, and abnormal heart rhythms. They can even be life-threatening. Postmenopausal women experience greater bone loss due to changing hormones and have more trouble absorbing calcium.

The best sources of calcium are dairy products such as milk, yogurt, cheese, calcium-set tofu, and small fish with bones. Vegetables like kale and broccoli also have calcium, and many cereals and grains are calcium-fortified.

What Causes Nutritional Deficiencies?

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The usual cause of nutritional deficiencies is a poor diet that lacks essential nutrients. The body stores nutrients, so a deficiency is usually caught after it’s been without the nutrient for some time.

A number of diseases and conditions — including colon cancer and gastrointestinal conditions — can lead to an iron deficiency. Pregnancy can also cause a deficiency if the body diverts iron to the fetus.

Researchers have found associations between bariatric surgery (surgery that reduces the size of the stomach to achieve weight loss) and nutritional deficiency. People who are candidates for bariatric surgery may already be nutrient deficient due to poor diet. Before and after the surgery, you should talk to your doctor and dietitian to set up a thorough nutrition plan.

What Are the Symptoms of Nutritional Deficiencies?

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The symptoms of a nutritional deficiency depend on which nutrient the body lacks. However, there are some general symptoms you might experience, including:

  • pallor (pale skin)
  • fatigue
  • weakness
  • trouble breathing
  • unusual food cravings
  • hair loss
  • periods of lightheadedness
  • constipation
  • sleepiness
  • heart palpitations
  • feeling faint or fainting
  • depression
  • tingling and numbness of the joints
  • menstrual issues (such as missed periods or very heavy cycles)
  • poor concentration

You may display all of these symptoms or only groups of them. Over time, most people adapt to the symptoms. This can cause the condition to go undiagnosed. Schedule a checkup with your doctor if you experience prolonged periods of fatigue, weakness, or poor concentration. These symptoms could be a sign of the beginning of a serious deficiency.

How Are Nutritional Deficiencies Diagnosed?

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Your doctor will discuss your diet and eating habits with you if they suspect you have a nutritional deficiency. They will ask what symptoms you’re experiencing. Make sure to mention if you have suffered from any periods of constipation or diarrhea, or if blood has been present in your stool.

Your nutritional deficiency may also be diagnosed during routine blood tests, including a complete blood count (CBC). This is often how doctors identify anemia.

How Are Nutritional Deficiencies Treated?

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The treatment for a nutritional deficiency depends on the type and the severity of the deficiency. Your doctor will find out how severe the deficiency is, as well as the likelihood of long-term problems caused by the lack of nutrients. They may order further testing to see if there is any other damage before deciding on a treatment plan. Symptoms usually fade when the correct diet is followed or supplemented.

Dietary Changes

A doctor may advise you on how to change your eating habits in the case of a minor deficiency. For example, anemia sufferers should include more meat, eggs, poultry, vegetables, and cereals.

Your doctor may refer you to a dietitian if your deficiency is more severe. They may recommend keeping a food diary for a few weeks. When you meet with the dietitian, you’ll go over the diary and identify changes you should make.

Typically, you will meet with the dietitian regularly. Eventually, you may have a blood test to confirm that you’re no longer deficient.


The federal government’s Dietary Guidelines for Americans recommends that you get most of your nutrients from food. In some cases, you may need to take supplements or a multivitamin. It may also be necessary to take an additional supplement to help your body absorb the supplements, such as taking calcium and vitamin D together.

The frequency and dosage of a supplement will depend on how severe the deficiency is. This will be decided by your doctor or a dietitian.

You should talk to your doctor before taking any nutritional supplements.

Parenteral Administration

In very severe cases, such as when a nutritional deficiency doesn’t respond to oral medications, it may be necessary for the nutrient to be given parenterally (through the veins or muscles). This can carry the risk of additional side effects. It’s usually done in a hospital.

Parenteral iron, for example, can cause side effects, including:

  • chills
  • backache
  • dizziness
  • fever
  • muscle pain
  • fainting

In rare cases, it can even cause a severe allergic reaction. Once you have been given the treatment, your doctor will have you do a repeat blood test to confirm that it was successful. You may need to attend the hospital for repeat appointments until you’re no longer deficient.

Will a Nutritional Deficiency Cause Long-Term Problems?

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Most problems caused by nutritional deficiencies will stop once you’re no longer deficient. However, in some cases, there may be lasting damage. This usually only occurs when the deficiency has been severe and has lasted a long time.

For example, a prolonged vitamin B-1 deficiency can be associated with:

  • stunted growth
  • depression
  • a form of dementia known as Wernicke-Korsakoff syndrome

Nutritional deficiencies in children can be serious and lead to lasting negative health outcomes.

If you’re experiencing symptoms and are concerned that you aren’t obtaining enough of a certain nutrient, talk to your doctor. They can discuss your diet with you and help figure out whether you should make some dietary changes or start taking supplements.

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