Biotin (Vitamin B7)

Biotin, also known as Vitamin B7, is an essential water-soluble B-complex vitamin that plays a key role in the body’s metabolism. The Vitamin B7 (Biotin) Test measures the amount of biotin in the blood to help evaluate an individual’s vitamin B7 status. Biotin functions as an important cofactor for several enzymes involved in fatty acid synthesis, glucose production, amino acid metabolism, and energy generation. The body obtains biotin primarily through foods such as egg yolks, liver, nuts, seeds, fish, avocados, and whole grains. Small amounts are also produced by beneficial bacteria in the intestine. Adequate biotin levels are important for maintaining normal metabolic processes, supporting nervous system function, regulating gene activity, and promoting healthy skin, hair, and nails. This test is mainly used to identify biotin deficiency, investigate symptoms that may be related to low biotin levels, and monitor individuals who may be at increased risk of deficiency. It is also important to note that high-dose biotin supplements can interfere with several laboratory tests- including thyroid function tests, hormone assays, and cardiac biomarker tests- sometimes leading to inaccurate or misleading results.

Who should get this test done?

This test may be recommended for individuals who:

●     Have symptoms of Biotin deficiency, including hair loss, brittle nails, or skin rash.

●     Are infants or children with unexplained neurological symptoms where inherited Biotin-related disorders are suspected.

●     Are pregnant and at increased risk of Biotin deficiency.

●     Take high-dose Biotin supplements and need monitoring or evaluation of possible laboratory test interference.

●     Have received prolonged total parenteral nutrition (TPN) without adequate Biotin supplementation.

Why consider this test?

This test is important for:

●     Diagnosing Biotin deficiency in individuals with symptoms such as hair loss, brittle nails, skin rash, or neurological problems.

●     Detecting inherited disorders of Biotin metabolism, including Biotinidase Deficiency and Holocarboxylase Synthetase (HCS) Deficiency.

●     Evaluating unexplained neurological symptoms such as seizures, ataxia, neuropathy, or developmental delay, particularly in infants and children.

●     Investigating skin, hair, and nail abnormalities that may be related to Biotin deficiency.

●     Assessing deficiency risk in individuals with excessive raw egg white consumption, malabsorption disorders, or prolonged anticonvulsant or antibiotic use.

More Information

Biotin has become increasingly important in laboratory medicine because high-dose supplements- commonly taken for hair, skin, and nail health- can interfere with several blood tests, including thyroid, cardiac troponin, and Vitamin D assays, leading to potentially misleading results. Patients are often advised to stop taking biotin supplements 48–72 hours before testing. Biotin is also essential for normal fat, carbohydrate, and protein metabolism, and deficiency can cause symptoms affecting the skin, hair, and nervous system. Rare inherited disorders such as Biotinidase Deficiency are included in newborn screening programs because early detection and treatment can prevent serious long-term complications.

Other names

●     Biotin Test

●     Serum Biotin Test

●     Biotin – Blood Test

●     Vitamin H Test

●     Coenzyme R Test

●     Serum Biotin Level

●     Biotin Nutritional Assessment

●     Biotin Deficiency Screen

●     Plasma Biotin Test

●     Biotin – Vitamin B7 Assay

●     Biotin Cofactor Test

●     Biotinidase Activity Test (related test for enzyme deficiency screening)