Biotin, also known as vitamin B7, is a water-soluble nutrient essential for converting food into energy, supporting healthy skin, hair, and nails, and regulating key metabolic and genetic processes. While deficiency is rare, it can lead to a range of health concerns—especially in certain high-risk groups.

In this guide, you'll learn how to recognize biotin deficiency, what causes it, and how it can be diagnosed and managed effectively.

What Are the Symptoms of Biotin Deficiency?

Symptoms usually develop gradually and can vary depending on the severity of the deficiency. Common signs include:

  • Thinning hair or hair loss, including eyebrows and eyelashes

  • Scaly rashes around the mouth, nose, eyes, and genital area

  • Brittle nails

  • Conjunctivitis (pink eye)

  • Seizures

  • Fatigue or low energy

  • Tingling or numbness in the hands and feet

  • Depression or mood changes

  • Developmental delays in infants

  • Unusual fat distribution on the face

In severe cases, biotin deficiency can lead to metabolic acidosis, where excess acid builds up in the blood. This can be life-threatening if left untreated.

Who Is at Risk? Causes of Biotin Deficiency

Although biotin is found in a wide variety of foods and is even produced by gut bacteria, certain factors can increase your risk of deficiency.

1. Biotinidase Deficiency (Genetic Condition)

This rare inherited disorder prevents the body from recycling biotin effectively. It comes in two forms:

  • Profound deficiency (less than 10% enzyme activity): May cause serious neurological issues if untreated in infancy

  • Partial deficiency (10–30% activity): May show mild or no symptoms

Incidence:

  • Profound: ~1 in 80,000 people

  • Partial: ~1 in 31,000–40,000 people

2. Alcohol Use Disorder

Chronic alcohol use can:

  • Reduce intestinal absorption of biotin

  • Lower expression of SMVT proteins responsible for vitamin uptake

Approximately 15% of individuals with alcohol use disorder show signs of biotin deficiency.

3. Pregnancy and Breastfeeding

Up to 50% of pregnant individuals may have low biotin levels due to increased nutrient demands. Biotin deficiency in pregnancy has been linked to risks such as preterm birth and restricted fetal growth, particularly in cases of hyperemesis gravidarum (severe pregnancy-related nausea and vomiting).

4. Excessive Raw Egg White Consumption

Raw egg whites contain avidin, a protein that binds to biotin and prevents its absorption in the gut. Consuming large amounts of raw eggs over time can deplete biotin levels.

5. Certain Medications and Medical Conditions

Some medications and conditions interfere with biotin absorption or increase its excretion:

  • Antiseizure drugs

  • Isotretinoin (acne medication)

  • Long-term antibiotics

  • Smoking

  • Aging

How Is Biotin Deficiency Diagnosed?

In Newborns

All U.S. newborns are screened for biotinidase deficiency through routine blood tests.

In Children and Adults

If symptoms are present, your provider may order:

  • Blood and urine tests to measure biotin levels or related enzymes

  • Nutrient panels to rule out other vitamin deficiencies

  • Genetic tests (if biotinidase deficiency is suspected)

Treatment Options for Biotin Deficiency

The treatment depends on the underlying cause:

For Biotinidase Deficiency

  • Lifelong supplementation with 5–20 mg of biotin per day is required

  • Early diagnosis is critical—neurological damage caused by delays in treatment may be irreversible

For Other Causes

  • Stop consuming raw eggs if avidin intake is the issue

  • Switch medications (if appropriate) that interfere with biotin absorption

  • Take oral biotin supplements as recommended by your healthcare provider

Biotin supplementation typically corrects mild deficiencies within a few weeks.

Living With Biotin Deficiency

Long-Term Outlook

With proper treatment, most people with biotin deficiency—whether genetic or acquired—can live full, healthy lives.

However, untreated profound biotinidase deficiency may lead to:

  • Vision loss

  • Hearing impairment

  • Developmental delays

  • Recurrent infections

  • Neurological damage or coma

This is why early detection and supplementation are essential, especially in infants.

Frequently Asked Questions

What foods are rich in biotin?

Biotin-rich foods include:

  • Egg yolks (cooked)

  • Salmon

  • Liver and pork

  • Sweet potatoes

  • Sunflower seeds

  • Almonds

  • Spinach

  • Whole grains

Can you take biotin daily?

Yes—but unless prescribed, most people don't need daily supplements if they eat a balanced diet. Also, high-dose biotin can interfere with lab tests, especially thyroid and hormone panels.

Can you take biotin and vitamin D together?

Yes, they can be taken together. However, let your provider know if you’re on biotin supplements, as high doses may affect vitamin D lab test accuracy.

Final Thoughts

Biotin plays an essential role in energy metabolism and maintaining the health of your hair, skin, and nervous system. While deficiency is uncommon, it's more likely in people with specific health conditions, dietary habits, or during pregnancy.

If you notice symptoms like unexplained fatigue, thinning hair, or skin changes—and especially if you’re in a high-risk group—consult a healthcare provider. Timely diagnosis and appropriate supplementation can restore biotin levels and prevent serious complications.