What Are the Most Common Vitamin Deficiencies?

What is a vitamin deficiency?

A vitamin deficiency occurs when you don’t get enough of a particular vitamin. And while there are a few common vitamin deficiencies, those vary widely, depending on where you live and your lifestyle choices.

The most common cause of a vitamin deficiency is simply not getting enough of a particular — or even multiple — vitamins. This is referred to as a primary deficiency. When a deficiency is a result of an underlying disorder that interrupts malabsorption, it's referred to as a secondary deficiency.

So which vitamin deficiency is the most common worldwide? Each region and group of people suffer from different vitamin deficiencies. Most governments now set guidelines regarding appropriate intakes. Some countries also have mandated vitamin food fortification programs to counteract the deficiencies.

These guidelines are typically different for men vs women vs the elderly vs children. The guidelines are often also different for pregnant and lactating mothers, as they require more nutrients for their children.

In the United States, we use the Recommended Dietary Allowances (RDAs). This set of guidelines was first established in 1941. It was set up by the Food and Nutrition Board of the National Academy of Sciences. Occasionally, these recommendations are not only updated but also revised to include certain groups of people. Sometimes the requirements are higher to counteract the most common vitamin deficiency in vegetarians and any other people who aren't getting enough through food alone.

How common are vitamin deficiencies, in general?

It turns out the majority of people may have a vitamin deficiency. In an overfed country that remains undernourished, vitamin deficiencies can occur even if you follow what you believe is a perfect diet.

Why is this happening? In the U.S., a lot of people eat too much processed food. For some people, eating nutritious food is simply too expensive. The fact that many families do not have access to healthy, well-balanced diets contributes significantly to the most common vitamin deficiencies in the U.S.

Additionally, soil all over the world has been depleted of nutrients. When food is grown in this soil, it no longer receives the same level of nutrients it once did. Studies show our soil's nutrient levels continue to decrease, leaving our most vulnerable populations at risk. So even when junk food and processed foods are avoided, people may still struggle to get adequate nutrition from their diet.

The lack of nutrients — combined with declining physical activity as a result of 9-to-5 jobs — has led to a large part of the population to suffer from chronic diseases. The U.S. Department of Health and Human Services claims that half of the United State’s population suffers from a preventable chronic disease.

Additionally, research suggests one-third of adults in the United States are now considered obese.

How can we fight back against the most common vitamin deficiencies in the United States? First, we have to understand what vitamins we’re lacking and take steps toward making healthier choices.

Most Common Vitamin Deficiencies

While some vitamin deficiencies are more common than others, they also vary from one group to the next. The most common vitamin deficiency in women may not necessarily be the same as the most common vitamin deficiency in children. That's why it's important to look at the big picture.

According to the U.S. Department of Agriculture (USDA):

• 90% of American may be deficient in potassium
• 70% may lack calcium
• 80% aren't getting enough Vitamin E
• Nearly 50% of the population doesn't get enough Vitamin A, Vitamin C, Vitamin D or magnesium
• 90% of Americans of color have a Vitamin D deficiency
• 70% of elderly Americans struggle with a Vitamin D deficiency

In addition, some groups of people are more susceptible to vitamin deficiencies than others.

Take pregnant women, for example. The most common vitamin deficiency in pregnancy occurs as the developing fetus requires more nutrition from the mother. According to the World Health Organization (WHO), many pregnant women struggle to maintain adequate levels of vitamin A, iron, iodine and folate.

People who choose not to consume meat, i.e. vegetarians, or any food derived from animals, i.e. vegans, are also more susceptible to vitamin deficiencies. Studies show that some of the most common vitamin deficiencies in vegans include Vitamin D, Vitamin B12, iodine, calcium and zinc.

Furthermore, the elderly population is at risk for many vitamin deficiencies. As the body gets older, it becomes harder to absorb essential vitamins and nutrients. Research indicates that the most common vitamin deficiency in elderly populations might be Vitamin D, but elderly individuals also tend to lack calcium, magnesium, Vitamin C, Vitamin B6 and Vitamin E.

With all that in mind, let's take a closer look at some of the most common vitamin deficiencies.

Vitamin D

Vitamin D is a fat-soluble vitamin that works like a steroid within the body. As it travels through the bloodstream, it enters your cells and alerts your body when genes should be turned on or off. Unlike some vitamins, your body is able to produce Vitamin D on its own as you expose your skin to sunlight.

Studies show that people living at great distances from the equator are more likely to have a Vitamin D deficiency because of the lack of sunlight. Some research indicates 42% of the population — including 74% of all elderly people and 82% of people of color — may be Vitamin D deficient.

Unfortunately, it's not always clear you’re dealing with a Vitamin D deficiency. The symptoms tend to be subtle and may not show up at all for decades. Vitamin D deficiency symptoms include bone loss, muscle weakness and a higher chance of bone fractures.

When children are deficient, it can lead to rickets and growth delays. Studies also suggest Vitamin D deficiency may lead to an impaired immune system and a higher risk of certain cancers.

According to the Office of Dietary Supplements, people are at risk of Vitamin D deficiency once serum 25(OH)D falls below 30 nmol/L. Some people may be at risk of inadequacy at 30 to 50 nmol/L (12–20 ng/mL). Having a serum level of 50 nmol/L (20 ng/mL) or more is sufficient for most people.

It's recommended that most adults receive between 600 and 800IU of Vitamin D every day. To accomplish this, you may want to eat more fatty fish or egg yolks. Additionally, if you currently don’t spend any time in the sun, it wouldn't hurt to get a few minutes of natural sunlight every day.

Vitamin B12

Vitamin B12 is a water-soluble vitamin, otherwise known as cobalamin. It's needed for proper nerve and brain function, as well as blood formation. Every cell requires B12 to work correctly, but the body doesn't produce it, so you can only get it through food and supplements.

It's very difficult for vegans and vegetarians to get Vitamin B12 naturally because it is mainly found in animal foods, other than some varieties of seaweed. That's why up to 90% of vegetarians and vegans may be Vitamin B12 deficient. Research also suggests that over 20% of elderly individuals may also be deficient because of the inability to absorb Vitamin B12 as the body ages.

The body doesn’t absorb Vitamin B12 like most vitamins, however. There is a protein (intrinsic factor) that must aid the absorption. When someone lacks this protein, B12 injections are required to get the proper dosage. Symptoms of vitamin B12 deficiency can be serious and include elevated homocysteine levels, impaired brain function, plus megaloblastic anemia.

The Office of Dietary Supplements suggests that serum levels below 170–250 pg/mL indicate a Vitamin B12 deficiency. The recommended daily intake is 2.4-2.8 mcg, which should be achieved through diet, if possible. Vitamin B12-rich foods include shellfish, organ meat, beef, eggs and dairy products.

Vitamin A

Vitamin A is another fat-soluble vitamin. This essential vitamin is needed to maintain healthy bones, teeth, cells and skin. It's also beneficial for eye health, as it produces pigments required for vision. Your body needs two types of Vitamin A: preformed vitamin A, which is found in many animal products, and provitamin A, which is in plant-based foods and is often called beta carotene.

For the most part, the Western diet supplies more than enough Vitamin A for the majority of people. However, it is one of the most common deficiencies in developing countries. Studies show nearly 50% of preschool children in some regions suffer from a Vitamin A deficiency.

Symptoms of Vitamin A deficiency include eye damage that could be permanent, a suppressed immune system and increased mortality rates, specifically among pregnant women and their children.

The Office of Dietary Supplements suggests that plasma retinol concentrations lower than 0.70 micromoles/L indicate inadequacy, while concentrations of 0.70–1.05 micromoles/L could signify a risk.

If you want to get more preformed Vitamin A, you should consume more organ meat, but if you’re still unable to get enough, you should talk to a doctor about a fish liver oil supplement.

There are many sources of beta carotene. Consider consuming more sweet potatoes, green leafy vegetables and carrots. There's virtually no chance of consuming too much beta carotene.

Vitamin C

Vitamin C is an essential vitamin that is a big part of most diets in developed countries. In fact, a deficiency is quite rare in the United States, with research indicating only about 7% of American adults suffer from a lack of Vitamin C. That being said, it becomes harder to absorb Vitamin C when you eat a poor diet or consistently consume too much alcohol.

Vitamin C deficiency symptoms include rough, bumpy skin, corkscrew-shaped hair, spoon-shaped fingernails, dry skin, an increased ability to bruise and slow healing wounds. It can take months for severe symptoms to show up, but it can eventually lead to scurvy.

The Office of Dietary Supplements suggests a total body content of Vitamin C of between 300 mg and about 2 g, with the lower numbers indicating scurvy. Most adults should consume between 75 and 120 mg of Vitamin C every day. Fortunately, there are plenty of vitamin C-rich foods to choose from.

To ensure you receive more than the recommended amount of Vitamin C daily, you should eat more acerola cherries, guavas, blackcurrants, sweet red peppers, kiwis, lychees, lemons, oranges, rose hips, strawberries, papayas, broccoli or parsley.

Folic Acid (Vitamin B9)

Folic acid is a B vitamin that is needed to make and repair DNA while also producing red blood cells. You are at-risk for a Vitamin B9 deficiency if you don't eat enough folic acid-rich foods, you consume too much alcohol or you deal with digestive conditions, such as celiac disease. You might also have trouble absorbing enough of this vitamin if you take seizure medication or if you are pregnant.

While most people get enough folic acid, it's still possible to develop a deficiency. Vitamin B9 deficiency symptoms include pale skin, irritability, decreased appetite, diarrhea and a smooth, tender tongue.

The Office of Dietary Supplements suggests that serum folate concentration values above 3 ng/mL indicate adequacy. This indicator is sensitive to recent dietary intake, so it isn't used for long-term status.

Adults should consume between 400-600 mcg DFE folate daily.

Folate is most important during pregnancy. Studies show that folate deficiency in pregnancy can cause birth defects. To counteract this threat, most prenatal vitamins contain an adequate amount of folic acid.

However, it's also possible to get enough folic acid through diet alone by consuming more green leafy vegetables, peas, Brussel sprouts, citrus fruits and eggs. It's also wise to consume tomato juice, bananas, melons, beans, legumes, asparagus and mushrooms if you want to add more folic acid to your diet.

How to Determine if You Have a Vitamin Deficiency

If you’re worried about these common vitamin deficiencies, you can easily determine whether or not you’re experiencing one. First, it's always best to assess your symptoms. If you aren't feeling like yourself, you might be able to pinpoint the cause simply by assessing how you’re feeling day-to-day. However, some vitamin deficiency symptoms overlap, leaving you wondering which one is actually the culprit.

In conjunction with looking at your symptoms, consider any recent changes you’ve made that could be affecting your health. Are you taking new medications or did you alter your diet in any way? If so, you may be able to determine what you are lacking and make the appropriate changes to your diet.

If you’re still in the dark once you've performed your own assessment, it's best to consult with your doctor. Your healthcare professional might be able to offer more insight into what's happening to see if there are changes that need to be made. If the symptoms alone don't lead your doctor to an answer, a blood test may be required. You can get a test to look for specific vitamin deficiencies. However, if it’s not clear what the cause is, it may be best to consider a complete blood panel instead.

How to Combat Vitamin Deficiencies

The easiest way to deal with vitamin deficiencies is to simply change your diet. By incorporating a healthy, well-balanced diet, you can be confident you’re getting all the nutrients you need.

However, this solution isn't always clear-cut, especially if you have special dietary needs. Whether you are vegan or have diet restrictions, you’ll want to research ways to get the nutrients you’re lacking.

Additionally, if you have underlying conditions that are preventing you from absorbing nutrients, you will need to speak with your doctor about a solution. In some cases, your healthcare professional will recommend shifting medications or incorporating a supplement to make up for what's lacking.

There are plenty of high-quality supplements on the market. And while it may seem best to take a multivitamin, that may not be the best solution if you only lack a few nutrients. In fact, taking a multivitamin might provide too much of the nutrients you’re already consuming through your diet. For this reason, it's often suggested to choose individual supplements and vitamins as needed.

You can ask your doctor for recommendations on which brands to take. Some vitamins contain toxic ingredients that can cause more harm than good. Any supplement you take should have reports from third-party testing, showing you the purity and ingredients. If not, you should take it.

With a few simple steps, you can avoid developing vitamin deficiencies and live a healthier life. Eat a well-balanced diet, avoid refined sugars and make healthy choices every day to ensure you’re receiving enough of every essential vitamin and maintaining your overall well-being.