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Vitamin Deficiency Test

Written by Ada’s Medical Knowledge Team

Updated on

A vitamin deficiency test is a laboratory test to diagnose a micronutrient deficiency. Our body needs micronutrients, including vitamins and minerals. Even though we need only tiny quantities of these substances, they're critical for our health and well-being. Deficiencies in any vitamin or micronutrient can lead to serious health conditions.

At present, more than 30% of people in the United States are at risk of a vitamin deficiency. 1

Let’s find out who might be at risk and when to take a vitamin deficiency test.

What is a vitamin deficiency test?

A vitamin deficiency test, or nutrients test, assesses vitamin or mineral levels in the blood. Either finger-prick blood tests or venous blood tests are available to collect blood.

You can perform a finger-prick test on your own using a lancet to prick your finger so you can collect blood. Alternatively, a nurse can collect venous blood for a venous blood test. This means blood is taken out from a vein and analyzed.

The vitamin and mineral deficiency test provides information about micronutrient blood levels. If you have too little of a vitamin or mineral, you have a deficiency and might need to take a supplement.

Vitamins and micronutrients are crucial for your health. They're involved in almost all processes in the body, including the production of enzymes and hormones. They're also necessary for physical and mental development. 2

What are the symptoms of vitamin deficiencies?

The symptoms of a vitamin deficiency depend on which vitamin is lacking. Fatigue, lack of energy, weakness, and dizziness are all symptoms of vitamin and micronutrient deficiencies.

Severe deficiencies can cause serious health issues such as poor physical and mental development in children, blindness, or vulnerability to disease. Many people experience deficiencies of:

A lack of vitamin B12, iron, or folate, can lead to anemia, which means low levels of healthy red blood cells. Red blood cells are needed to transport oxygen through the body. People with too few red blood cells experience tiredness, weakness, headache, pale or dry skin, and dizziness. 3

How to test for vitamin deficiency?

There are vitamin blood tests to test for vitamin deficiency. You can either do a test yourself at home, or ask your doctor to perform a test at the clinic. The principle is the same for both.

The first step is to collect blood, either by a finger-prick test or by collecting venous blood. The next step is to send the blood sample to a laboratory. The laboratory will then test the levels of vitamins and minerals. The results will usually be available within a few days.

Who should take a vitamin deficiency test?

A balanced diet usually provides most people with enough vitamins and minerals. However, some people are at risk of experiencing vitamin deficiency due to various reasons. They should think about taking a blood test for vitamin deficiency screening.

Pregnant women and small children are at significant risk for nutrient deficiency. This is because they require higher doses of micronutrients. Vitamins and micronutrients are essential for childhood development, and deficiencies can have severe effects on child and mother. 4

Furthermore, the following conditions are likely to cause vitamin deficiencies:

  • Gastrointestinal disorders that result in lower nutrient absorption such as Crohn’s or celiac disease
  • An unbalanced diet
  • Vegan diet
  • Excessive alcohol consumption
  • Taking certain medications that decrease nutrient consumption such as proton pump inhibitors
  • Living in regions with little sunshine

If you belong to a risk group or experience any of the deficiency symptoms described above, you may think about doing a vitamin deficiency test.

What is included in an at-home vitamin deficiency test?

If you want to perform an at-home vitamin deficiency test with a vitamin test kit, your first step will be to decide which vitamin to test for. You can test for only 1 micronutrient or multiple vitamins with one kit. Such a vitamin panel blood test usually tests for the most common vitamin deficiencies, including vitamin D, B vitamins, folic acid, and others.

The test kit includes all materials needed to collect a small blood sample. There is an alcohol wipe to clean your skin, a lancet to prick your finger, and a blood collection tube. A transport tube, and an envelope to send your sample to the laboratory, will also be included.

What to do with the results of the nutrients test?

The results of your nutrient blood test will not only give you information about your blood level of a specific vitamin. It will also include information about the reference blood levels and whether you are within or outside that normal range. If your blood levels are below the reference level, you may think about supplementing the vitamin. Speak to your doctor if you are unsure what to do with your results.


Q: Why test for vitamin deficiency?

Vitamins and micronutrients are involved in almost every process in your body and are, therefore, essential for your health. Testing for vitamin deficiency is important if you belong to a risk group. You can supplement the vitamin and avoid severe deficiency symptoms based on the results.

Q: Where can I take a vitamin test?

You can take a vitamin test at home with an at-home vitamin deficiency test or speak to your doctor to do it in the clinic.

Q: What to do if the results show a vitamin deficiency?

If your vitamin deficiency test results show that your nutrient blood levels are too low, you may talk to your doctor about supplementing the vitamin. You may also consider adjusting your diet and eating foods rich in those vitamins.

Q: How often should blood vitamin levels be checked?

There's no general rule on how often to do a vitamin levels test. If you already have a diagnosed deficiency, talk to your doctor to see if a regular vitamin blood levels test is necessary.