Many nutrients are required for daily functions of the body and essential for good health throughout the lifespan.
A proper, balanced diet can provide all the nutrients you need every day from foods; however, the Western diet is low in a variety of very important nutrients (1). This includes macronutrients – carbohydrates, proteins, and fats – and micronutrients – vitamins and minerals.
Deficiencies in micronutrients – vitamins and minerals – are most common when it comes to having a poor diet. Micronutrient deficiencies are especially important because these nutrients are involved in all types of bodily functions from cell growth to brain function.
At least a third of America’s population is deficient in one, two, or three vitamins. This can give rise to a variety of symptoms to poor, chronic health outcomes with prolonged deficiency.
What are ‘vitamins’ and why are they important
Vitamins are organic substances and are important micronutrients for many functions in the body.
Some of these vitamins the body can make. These are called ‘non-essential vitamins.’ An example of a non-essential vitamin would be Vitamin D, which the body produces from sunlight.
Other vitamins the body cannot make and have to be consumed from the diet on a daily basis. Examples of essential vitamins are Vitamin C and Vitamin E.
In total, there are 13 vitamins – either water-soluble or fat-soluble – that the body requires to run properly, especially when it comes to a crucial function like maintaining a normal metabolism (2).
Not consuming enough of every vitamin can result in harmful health conditions.
What is a ‘vitamin deficiency,’ what are the risks, and how common is it?
As stated above, vitamin deficiencies may lead to a horde of chronic health problems.
A ‘vitamin deficiency’ is the condition of a long-term under-consumption of a vitamin. Deficiencies in essential vitamins are quite common for those following a typical Western diet and lifestyle, which is low in a variety of very important nutrients – including several vitamins (1).
Vitamin deficiencies affect around a third of the American population. Some certain vitamins are an even higher percentage; like vitamin D, which over 40% of Americans are deficient in (3).
The 7 most common vitamin deficiencies in Americans
There are 13 recognized vitamins; all of which are essential for basic body functions.
Of these vitamins, 7 of them are very common to be deficient in at least a third of the American population. These include vitamins D, B12, A, B9, B2, B6, and C.
- Vitamin D
Vitamin D is a fat-soluble, a non-essential vitamin linked to several important functions of the body. It is a nutrient the human body can produce when in contact with sunlight, hence it’s nickname – ‘the sun vitamin.’
An adequate amount of vitamin D is important to maintain health throughout the lifespan. This essential nutrient is part of building strong bone tissue (along with calcium), boosting brain health, and proper immune system function.
The recommended daily amount of vitamin D is 400–800 IU (10–20 mcg), but vitamin D deficiency is a very common issue affecting over 40% of Americans who lack exposure to sunlight (3).
Vitamin D deficiency can lead to fatigue and unstable mood, hair loss, muscle weakness and pain, osteoporosis, decreased wound healing, and increased risk of fracture (3).
- Vitamin B12
Vitamin B12 – aka: cobalamin – is a water-soluble vitamin that plays an essential role in nerve function, DNA production, cell metabolism (energy production), and red blood cell formation.
B12 is most commonly found in poultry, meat, fish, and animal by products, like yogurt, cheese, and eggs. It can also be found in fortified cereals. However, deficiency in vitamin B12 is not unheard of in Americans. Deficiency is most common for individuals following a vegetarian or vegan diet who do not eat animal products or byproducts.
Common symptoms of B12 deficiency can include anemia, fatigue, muscle weakness, intestinal problems, nerve damage and mood disturbances (4).
The recommended daily amount of vitamin B12 is 1.8 mcg. This amount is increased for children and pregnant or breastfeeding women.
- Vitamin A
Vitamin A isn’t actually a single vitamin, but a group of fat-soluble vitamins, including retinol, retinal, and retinyl esters. Because it is ‘fat-soluble,’ vitamin A can be stored in the body tissue for later use.
Two of these forms of vitamin A can be found in foods. Retinol and retinyl esters are found in animal products and byproducts while carotenoids are abundant in fruits, vegetables, and plant-based oils (5).
Vitamin A is essential in cell growth, immune health, and fetal development, but is most commonly associated with its role in eye health. This vitamin is involved in keeping the eye health from color vision, low-light, and maintaining and protecting the cornea (5).
The RDA of vitamin A is 700-900mcg for adults and the upper limit is 3,000mcg per day (to avoid toxicity). The most common issue with not meeting the recommended intake of vitamin A is poor eye health and night-blindness.
- Vitamin B9 (Folic Acid or Folate)
Vitamin B9 comes in two forms – folic acid or folate.
Folate is the naturally occurring form of vitamin B9 and is most commonly found in leafy vegetables like kale and cabbage.
Folic acid is the synthetic form of the vitamin. Folic acid is actually more preferred over folate because it is more easily activated and absorbed in the digestive system (6).
Vitamin B9 is one of the most important micronutrients and needed throughout the lifecycle, but is essential during pregnancy and childhood. This vitamin is important for producing DNA and building new cells and is required for normal growth (7).
When deficiency occurs, harmful defects can occur in fetuses, including neutral tube defects and improper brain development. Research also suggests it may also help prevent deformations like cleft lip and cleft palate.
- Vitamin B2 (Riboflavin)
Vitamin B2—also called riboflavin—helps the body complete the process of metabolism. The process of metabolism is meant to create energy from food, specifically macronutrients – carbohydrates, proteins, and fats.
This B vitamin also helps to keep the skin, intestinal lining, and blood cells healthy (8).
The recommended daily allowance of vitamin B2 is 1.3mg per day for men and 1.1mg per day for women. This changes for pregnant and breastfeeding women, who should consume 1.4mg and 1.6mg of vitamin B2 per day, respectively (8).
Symptoms of B2 deficiency includes frequent acne breakouts, fatigue, migraine headaches, and cataracts.
- Vitamin B6 (Pyridoxine)
Pyridoxine, the common name for vitamin B6, is vital for brain function. It is also essential for keeping the immune system and nervous system working properly (8). In infants and children, B6 is responsible for normal brain and nervous system development.
Vitamin B6 is found in food sources like poultry, fish, potatoes, bananas, and certain legumes, like chickpeas.
The recommended daily allowance of vitamin B6 for both adult men and women is 1.3mg per day. Consuming under this recommendation can lead to symptoms such as confusion, depression, and a higher occurrence of illnesses due to a weakened immune system.
Those at highest risk of vitamin B6 deficiency are those with kidney and malabsorption disorders, due to deduced capacity to absorb the nutrient in the digestive system (8).
- Vitamin C
Vitamin C—also known as ascorbic acid—is a water-soluble vitamin found in an abundant number of vegetables and fruits, primarily citrus fruits.
This micronutrient plays an important role in several vital body functions, which is why it needs to be consumed daily. These include supporting a healthy immune system, keeping bones strong, aiding in healing, helps in iron absorption, functioning as an antioxidant, and promoting healthy aging.
The recommended daily amount of vitamin C is 90mg for adult men. For adult women, the daily recommended intake is and 75mg (9).
If you are not consuming enough daily vitamin C, you may experiences symptoms such as weakness and skin disease. Because vitamin C is important for iron absorption, a vitamin C deficiency may also lead to anemia.
Why deficiency in these 7 vitamins matters
As you can see above, these 7 vitamins are a vital part of many functions in the body.
They are also the most common vitamin deficiencies in Americans. Affecting over a third of the American population.
This is caused by several factors – a Western diet and vegan or vegetarian diet, lifestyle choices, and/or chronic diseases that affect the absorption of micronutrients in the digestive system (1).
Deficiency in any vitamin is not ideal because under-consumption of a vitamin can lead to a horde of chronic health problems.
Short-term symptoms of vitamin deficiencies can include anything from fatigue to weakness to frequent acne breakouts. Long-term symptoms are more serious and can cause altered function in body systems (i.e., digestive system) (8). All if this, of course, depending on the vitamin.
What do you do if you are deficient in any of these (or other) vitamins?
If you feel you are suffering from a vitamin deficiency, the first step is to consult a trusted medical professional. A doctor can run clinical tests to determine your vitamin status.
If your tests come back that you are indeed vitamin deficient, then you can begin taking steps to meet your daily recommendations of each vitamins.
The first step to ensure you are consuming all your vitamins is lifestyle change. This can include more exposure to sunlight (i.e., for vitamin D production) and a healthier diet. A diverse diet of vitamin-dense foods like fruits, vegetables, meats, and animal byproducts will ensure adequate vitamin levels in the body.
However, if you are still not meeting your daily vitamin recommendations, then multivitamins or dietary supplements may be needed.
How to pick the best multivitamin for you
As stated above, the first steps to take in meeting your daily vitamin recommendations should be with lifestyle change. Also, a diversified diet high in vitamin-dense fruits, vegetables, meats, and animal byproducts.
If any of these alterations are not possible (i.e., you follow a vegan diet or suffer from a malabsorption disease), then a multivitamin or supplement may be necessary.
There is no set guideline for which multivitamin is best. You must choose the one you that is right for you, fits your lifestyle and values, and has all of the ingredients you need. However, whichever you happen to select, ensure you purchase a trustworthy brand and thoroughly review the usage instructions.
Is it possible to overconsume a vitamin?
It is always important to be aware that, especially when consuming multivitamins or dietary supplements, the opposite of deficiency can occur.
While ‘vitamin deficiency’ is the under-consumption of a vitamin, ‘vitamin toxicity’ is the over-consumption of a vitamin.
Vitamin toxicity is most common with fat-soluble vitamins then water-soluble. This is because fat-soluble vitamins are stored in the body tissues long after consuming them, while excess water-soluble vitamins are not stored and expelled with waste.
Examples of fat-soluble vitamins in the diet include vitamin A, D, E, and K.
Mild to serious signs and symptoms of vitamin toxicity can include (10):
Red, irritated skin
- Certain forms of anemia
- Kidney disfunction
Of course, the symptoms will always depend on the vitamin in question.
If you ever think you are showing signs of vitamin toxicity, seek medical advice immediately.
Seek advice from a medical professional
As stated above, the first thing to do when you suspect a vitamin deficiency is to seek advice from a medical professional. A doctor can run exhaustive tests to determine your vitamin status and confirm if you are actually suffering from deficiency.
If you are suffering from a vitamin deficiency and a healthy lifestyle and diet change is not enough, remember to choose a trustworthy brand of multivitamins to add to your daily diet.
If you experience any negative reactions and/or if a multivitamin may interact with medications your currently take, seek out the advice of a medical professional immediately.
Author: Allison Lansman, RDN, LD