Vitamin B7 (Biotin) – Benefits, Toxicity and More

Vitamin B7 found in egg yolks.

Introduction to Vitamin B7

You might be familiar with vitamin B7 from its common name, biotin. It is a B vitamin that dissolves in water and can be found naturally in some foods and supplements. Enzymes need biotin to help them break down macro-nutrients such as fats, carbohydrates, and proteins.

Biotin supplements are frequently praised for being a reliable treatment for hair loss and for promoting healthy hair, skin, and nails.

Food Sources
  • Sweet potato
  • Beef liver
  • Cooked egg,  the yolk in particular
  • Nuts, seeds
  • Salmon
  • Avocados
Health Benefits of Biotin

Most prominent health benefits of Biotin are;

  • Vitamin B7 is necessary for liver metabolism
  • Maintains proper nervous system function
  • Dietary supplement for skin care
  • Strengthens nails and hair
  • Maintains mucous membranes
  • Aids cell growth
Daily Required Dose
0-6 months5 mcg5 mcg  
7-11 months6 mcg6 mcg  
1-3 years8 mcg8 mcg  
4-8 years12 mcg12 mcg  
9-13 years20 mcg20 mcg  
14-18 years25 mcg25 mcg30 mcg35 mcg
19+ years30 mcg30 mcg30 mcg35 mcg

*These doses are for ideal conditions, consult your physician before supplementation*

Deficiency Symptoms

Common symptoms that appear due to the deficiency of Biotin are;

  • Thinning hair
  • Scaly skin rashes around eyes, nose, mouth
  • Brittle nails

Excessive alcohol can prevent the absorption of many nutrients. It can increase the risk of biotin deficiency and other nutritional deficiencies. Despite eating enough biotin, one out of three pregnant women exhibit a mild biotin deficiency, though the exact reason is unknown.

How to overcome the deficiency of Biotin?

To tackle the biotin deficiency, Biotin supplements and multivitamins can be purchased online or over the counter. However, the best source of B vitamins is a well-balanced diet.

Toxicity Symptoms

Due to the lack of evidence that biotin is toxic, the theorized maximum tolerable limit is 10,000 mcg.

However, taking too much biotin can cause symptoms in some individuals. Among these symptoms are:

  • Pain in the stomach (bloating),
  • Insomnia,
  • Excessive thirst,
  • Frequent urination.

Although biotin is frequently used as a supplement for the growth of hair and nails, little research has demonstrated its effectiveness. Biotin supplementation may be beneficial in cases of pathologies, such as brittle nail syndrome or uncalmable hair, as well as acquired and inherited causes of biotin deficiency. However, these instances are uncommon and there is insufficient evidence to support supplementation in healthy individuals.


About the Author

Saleh Siddiqui

Doctor of Pharmacy (Pharm. D) and Content Author at KeepUpFitness.

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