One of the essential vitamins is biotin, a cofactor for four enzymes with roles in intermediate metabolism. Biotin deficiency can be acquired: it can be due to inadequate biotin intake during parenteral nutrition, or due to consumption of raw egg white. Biotin deficiency can also be due to genetic defects in proteins that play an important role in biotin homeostasis.
Biotin deficiency can develop under a variety of circumstances. Within weeks to months, people on total parenteral nutrition lacking biotin, or infants fed on formula lacking biotin will start to display thinning or loss of hair and will develop scaly skin rashes, usually around the mouth, nose, and eyes. Similar symptoms develop in people who eat raw egg white for prolonged duration, which contains avidin, a protein that binds to biotin strongly. Neurological symptoms in adults include lethargy, depression, seizures, ataxia, and paresthesia of the hands and feet. Infants are also lethargic and have developmental problems. Other symptoms are acidosis and organic aciduria.
A milder form of biotin deficiency may develop because of increased catabolism of biotin. This may be caused by treatment with anticonvulsants  or by smoking . These are marginal effects, without the signs of overt deficiency. Pregnancy and lactation increase the demand for biotin  and thus, may also result in marginal biotin deficiency . However small degree of deficiency is also of crucial importance, as even marginal biotin deficiency can have teratogenic effects according to animal studies  . Chronic biotin deficiency may also develop in preterm infants fed on mother’s milk .
Biotin deficiency can also develop in people with genetic conditions affecting enzymes responsible for the metabolism of biotin . These include two vitamin transporters, which facilitate the movement of biotin into cells; a holocarboxylase synthetase, which binds biotin covalently to its target proteins; and biotinidase, which liberates free biotin from biotin containing peptides and biotinyl-lysine in the gastrointestinal system, and thereby plays a central role in the recycling and absorption of biotin. Biotinidase deficiency is an autosomal recessive condition. People with biotinidase defects present with symptoms similar to those of acquired biotin deficiency, but in addition have a hearing and vision loss  .
Entire Body System
Abstract Several of the clinical and biochemical manifestations of biotin deficiency also occur in severe protein-energy malnutrition (PEM). [ncbi.nlm.nih.gov]
Ziboh, Malnutrition‐Associated Rash of Cystic Fibrosis, Pediatric Dermatology, 17, 5, (337-347), (2001). Janos Zempleni and DonaldM Mock, Biotin biochemistry and human requirements, The Journal of Nutritional Biochemistry, 10, 3, (128), (1999). [doi.org]
Severe malnutrition due to poverty, ketogenic diet or eating foods very low in the vitamin may cause low levels of the vitamin B7 in the plasma. [allnutriments.blogspot.com]
Protein-energy malnutrition can affect wound healing. [podiatrytoday.com]
Abstract Here, a case is presented with two rare genetic disorders, biotinidase deficiency and juvenile myelomonocytic leukemia, in a Turkish infant. [doi.org]
Each patient had alopecia totalis, hypotonia, and developmental delay. Two developed the characteristic scaly periorificial dermatitis; one had only an intermittent scaly rash on the cheeks and occipital scalp. [ncbi.nlm.nih.gov]
The boy presented with perinatal distress followed by developmental delay, hypotonia, seizures, and infantile spasms without alopecia or dermatitis. [en.wikipedia.org]
Chief characteristics include weak muscles (hypotonia), seizures, hair loss (alopecia), an inflammatory skin rash (eczema), developmental delays, and lactic aciduria. [rarediseases.org]
These can be seen alone or in combination with eczema, psoriasis and dandruff. The belief for symptoms presenting in this manner is also closely linked to the integral part biotin plays in the metabolic process. [healthyhairplus.com]
Skin conditions: Eczema, psoriasis, seborrheoeic dermatitis, flaking, itching, scaly, dry or inflamed skin, sores in or around the mouth, burning mouth/tongue, all of these problems suggest biotin (or another B vitamin) deficiency. [gainesville.com]
It's commonly used to remediate neurological problems, hair loss (alopecia) and skin conditions (such as acne and eczema) associated with a lack of certain enzymes. [articles.mercola.com]
In recent years, several reports have shown that infants with food allergy and/or atopic eczema have developed MCD after being fed with peptide formulas. [ci.nii.ac.jp]
- Loss of Gait
: Late presentation of biotinidase deficiency with acute visual loss and gait disturbance. Dev Med Child Neurol 1997 ;39: 830 — 831. [doi.org]
- Cognitive Impairment
In one study, 2.5 mcg of biotin per day for at least 6 months improved nail thickness by 25 percent 6 Maintaining healthy skin Preventing age-related cognitive impairment or decline Biotin May Benefit Multiple Sclerosis Patients Interestingly, recent [articles.mercola.com]
Bioassays have been developed and used for the determination of biotin levels in blood. However, plasma concentrations measured by these methods are often not reliable indicators of the biotin status, partly because the assays may not distinguish between biotin and its inactive metabolites . The secondary effects of biotin deficiency can be measured through assessing the activities of biotin-dependent enzymes  . Biotin is an essential cofactor for two acetyl-CoA carboxylases, pyruvate carboxylase, propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase . Decreased activity of methylcrotonyl-CoA carboxylase leads to the accumulation of methylcrotonyl-CoA and to its conversion to 3-hydroxyisovaleric acid, which can be measured in the urine. The concentration of 3-hydroxyisovaleric acid is a good indicator of the biotin status  .
Recently a new liquid chromatography tandem mass spectrometry method has been developed for the measurement of the carnitine-bound substrate/product pairs for the biotin-dependent enzymes . Thus, this method affords the determination of the activity of several biotin-dependent enzymes and therefore provides a more robust assessment of the biotin status in cases of marginal biotin deficiency (such as may occur in pregnancy) than assays relying on just one enzyme activity.
Biotidinase activity can be measured from blood samples on paper discs, or in serum using colorimetric assays. Children with less than ten percent of normal serum enzyme activity present with severe biotinidase deficiency .
Other tests may include urine ketone and organic acid levels, and serum ammonia levels.
- Mock DM, Dyken ME. Biotin catabolism is accelerated in adults receiving long-term therapy with anticonvulsants. Neurology. 1997;49:1444–1447.
- Sealey WM, Teague AM, Stratton SL, Mock DM. Smoking accelerates biotin catabolism in women. Am J Clin Nutr. 2004 Oct;80(4):932-935.
- Perry CA, West AA, Gayle A, et al. Pregnancy and lactation alter biomarkers of biotin metabolism in women consuming a controlled diet. J Nutr. 2014 Dec;144(12):1977-1984.
- Mock DM, Stadler DD, Stratton SL, Mock NI. Biotin status assessed longitudinally in pregnant women. J Nutr. 1997;127:710–716.
- Mock DM. Marginal biotin deficiency is common in normal human pregnancy and is highly teratogenic in mice. J Nutr. 2009 Jan;139(1):154-157.
- Tokuriki S, Hayashi H, Okuno T, et al. Biotin and carnitine profiles in preterm infants in Japan. Pediatr Int. 2013 Jun;55(3):342-345.
- Zempleni J, Hassan YI, Wijeratne SS. Biotin and biotinidase deficiency. Expert Rev Endocrinol Metab. 2008 November 1; 3(6):715–724.
- Baykal T, Gokcay G, Gokdemir Y, et al. Asymptomatic adults and older siblings with biotinidase deficiency ascertained by family studies of index cases. J Inherit Metab Dis. 2005;28(6):903-912.
- Bogusiewicz A, Horvath TD, Stratton SL, Mock DM, Boysen G. Measurement of acylcarnitine substrate to product ratios specific to biotin-dependent carboxylases offers a combination of indicators of biotin status in humans. J Nutr. 2012;142(9):1621-1625.
- Neto EC, Schulte J, Rubim R, et al. Newborn screening for biotinidase deficiency in Brazil: biochemical and molecular characterizations. Braz J Med Biol Res. 2004 Mar. 37(3):295-299.