Vitamin Deficiency and How it Affects Chronic Disease

The majority of Americans are not meeting dietary recommendations. Someone can seem healthy, but a lack of essential nutrients can prevent necessary processes from occurring. For people who have a chronic disease, it's even worse to have vitamin or mineral deficiencies. Let's review the common deficiencies and how they will affect chronic conditions.

What Americans eat

According to,1 3/4 of the U.S population aren't getting enough fruits and vegetables. They are eating more than enough grains and proteins, but not the right kinds. They are eating too much salt, fat, and sugar.
This information comes from the NHANES (National Health and Nutrition Examination Survey)2 data, which is an ongoing study of health and nutrition in both adults and children. These studies have been going on for decades, and the current information is based on 2007-2010 data. This is the latest available data that's been fully processed for government use. If you want to see public data, they have partially published information for more recent years. You can view it on the USDA ARS website.3

Nutrients that Americans are missing from their diet

In 2009, WebMD published an article4 about seven nutrients that most Americans aren't getting enough of:
  • Calcium
  • Potassium
  • Fiber
  • Magnesium
  • Vitamin A
  • Vitamin C
  • Vitamin E
As I mentioned before, taking vitamins or other supplements is not the best way to make sure you're getting what you need.
It's better to get essential nutrients from whole food sources. It's often cheaper this way, too, because eating food means the nutrients are more bioavailable (absorbable). Taking supplements is usually equivalent to throwing away your money because your body can't properly use the nutrient in pill form. Not only that but taking supplements can sometimes cause a higher risk for certain serious conditions, such as cancer.

Consequences of poor nutrition in people with chronic illness

If you have any symptoms of a nutrient deficiency, please make an appointment with your health care provider to see if further testing or dietary adjustments are needed.
Let's look again at those missing nutrients, and see what the symptoms are when your body is deficient:

Calcium deficiency:

  • Muscle cramps
  • Numbness and tingling in the fingers
  • Convulsions
  • Lethargy
  • Poor appetite
  • Arrhythmia
  • Bone loss/osteoporosis, leading to increased risk of fracture
Typically, calcium deficiency does not have associated symptoms at first. But over time they will show up and can become life-threatening.
The risk for low calcium is common in women who no longer menstruate, either because they are postmenopausal or their periods have stopped due to body weight (eating disorder or athletes who work out strenuously). Lactose intolerance, cow's milk allergy, and avoidance of cow's dairy for other reasons (such as religious or personal beliefs) can also lead to low calcium, but these days non-dairy milk that contains calcium is readily available as a substitute.

Potassium deficiency:

You have to be especially careful with potassium supplementation because too much potassium can be as dangerous as too little. Here are some of the symptoms of low potassium:
  • High blood pressure
  • Kidney stones
  • Skeletal issues, including excessive calcium excretion
  • Increased sensitivity to salt in relation to blood pressure
  • Constipation
  • Fatigue
  • Muscle weakness
  • Increased urination
  • Encephalopathy (swelling in the brain)
  • Glucose intolerance
  • Paralysis
  • Poor respiration
  • Arrhythmia
Besides poor dietary intake, low potassium levels can also occur from chronic diarrhea, so those with IBS or inflammatory bowel disease are at increased risk. Deficiency is also more common in people who take diuretics (other than the potassium-sparing kind), laxatives and use enemas frequently. Pica (an eating disorder where things like clay are consumed) also puts people at higher risk, because clay binds to potassium and keeps it from getting adequately absorbed.

Fiber deficiency:

Not getting enough fiber can cause more problems than one might think. Besides constipation, low fiber intake can increase risks for weight gain, diabetes, nausea, fatigue, high cholesterol and other heart diseases, IBS, hemorrhoids, and even cancer.
People at risk for low fiber intake (and its symptoms) tend to be on high-protein, low-carb diets.

Magnesium deficiency:

  • Loss of appetite
  • Nausea
  • Vomiting
  • Weakness
  • Numbness
  • Tingling
  • Muscle cramps
  • Seizures
  • Personality changes
  • Arrhythmia
  • Coronary spasms
  • Calcium deficiency
  • Potassium deficiency
People with gastrointestinal issues, type 2 diabetes, alcoholics, and older adults all have a higher risk of magnesium deficiency.

Vitamin A deficiency:

Although vitamin A deficiency is uncommon in developed countries, not being breastfed (or not receiving enough colostrum/breast milk) can lead to a deficiency in infants. If not treated, it causes blindness. Chronic diarrhea can also increase the risk of vitamin A deficiency, which in turn can cause more diarrhea.
Night blindness is one of the first symptoms of xerophthalmia; other effects include dry eye and inflammation. Other risks from deficiency are increased mortality and infection, particularly in infants.
Premature birth and cystic fibrosis also increase the risk of deficiency.

Vitamin C deficiency:

You may have heard of scurvy, which is a severe vitamin C deficiency that happened to people who lived at sea for extended periods. Scurvy can occur within a month of very low or no vitamin C intake. It's very rare in developed countries, but cases do occur. Symptoms include fatigue and inflammation. Progressive disease can consist of poor wound healing, joint pain, broken blood vessels (petechiae), and bleeding gums/tooth loss.
Vitamin C also helps the body absorb iron, so over time iron-deficiency anemia can develop. Prolonged vitamin C deficiency will lead to death.
Populations at higher risk for vitamin C deficiency/scurvy are:
  • Smokers and people frequently exposed to second-hand smoke
  • Infants given boiled/evaporated milk instead of formula (calcium blocks vitamin C absorption, so this can also lead to anemia)
  • Anyone on a diet with minimal variety (including people who are on a strict diet, such as a high-protein diet; meat has little-to-no vitamin C); this includes the elderly population
  • People who have digestive malabsorption, some types of cancer, and end-stage renal disease
  • On the other hand, you don't want to overdo it on vitamin C. Higher doses can cause digestive problems including nausea, vomiting, and diarrhea.

Vitamin E deficiency:

Symptoms of vitamin E deficiency include:
  • peripheral neuropathy (weakness, numbness, or pain in the arms and/or legs)
  • ataxia (a nerve disease that affects the ability to walk, talk, swallow, cause tremors, and more)
  • impaired immune response (inability to fight off infections)
  • retinopathy and retinal degeneration (diseases of the eyes affecting vision)
  • skeletal myopathy (muscle weakness)
Although vitamin E deficiency is considered rare, people who have trouble absorbing fat are at risk, because this is a fat-soluble vitamin. Some conditions that block fat absorption are abetalipoproteinemia,5 Crohn's disease,6 cystic fibrosis,7 and people who have gallbladder8 or biliary tract disorders.9

What you can do if you think you have a vitamin or other nutrient deficiency

As you can see, not getting proper nutrition can be very dangerous and even fatal in some cases. Deficiencies can also mimic symptoms in other conditions, which can make it confusing for your doctor to treat your symptoms appropriately. As I mentioned in my other article about supplements, doctors get very little nutrition training. A nutritional issue may be the last thing they think about when they are trying to figure out what's wrong with you, and they are definitely not the experts in correcting it.
So if you are having any symptoms that you think are related to a dietary deficiency, ask your doctor to run tests. Even if you don't have symptoms, it might be a good idea. Most people don't realize that their diets are out of balance because they feel fine, or they attribute their symptoms to something else.
I hope that the descriptions above have convinced you that there is such a wide range of possibilities when it comes to inadequate nutrient intake, that symptoms need to be addressed before they get worse.
I also recommend that once testing is done, you have a registered dietitian or nutritionist give you advice about changing your diet. A doctor might have a few suggestions, or want you to take a pill to make your symptoms better. I can't stress enough that this is not the best thing for your body. If your doctor resists a referral, ask him or her point-blank how many hours of nutrition training they have. Doctors are not nutrition experts; that's what dietitians. If they won't refer you, consider making an appointment on your own and paying out of pocket.
You can also find out what types of foods contain each vitamin by going to the NIH Office of Dietary Supplements website (
I would say just eat more of certain foods, but there are a few problems with that:
  1. Even healthy foods can cause reactions in people if they are sensitive/allergic/intolerant to that food;
  2. If you are taking any medication or have a diagnosed condition, some foods may interact with your prescription or disease;
  3. If you are guessing what your dietary deficiency is, you may treat the wrong thing and/or make matters worse
I'm a strong proponent of evidence-based medicine because guessing and experimenting without all the facts is usually a waste of time, and often harmful. I spent many years before my diagnosis being a guinea pig for doctors. I ended up having so many tests done and taking so many medications, that soon I started having to take different drugs to counteract the side effects of the other prescriptions. And I never felt better, only worse.
While it still may take some trial and error with your diet to make sure you're getting all of your nutrient needs, in general, adding healthy foods to one's diet is inexpensive and has far fewer side effects than taking pills.