Vitamin B7 (biotin)
Biotin or vitamin H or vitamin B7 is a water soluble vitamin. It is also known as coenzyme R and Bios 2. Both biotin as well as its oxide derivative oxybiotin, where the sulphur in its molecule is replaced by oxygen, are biologically active. Biotin can actually occur as eight stereoisomers, D-biotin being biologically the most important of them. Vitamin H is also called an antiseborrheic vitamin. It is a vitamin that is stable in both the heat and the sunlight.
Which foods contain the vitamin?
- Whole grain bread
- Boiled soy beans
Biological functions of the vitamin
Biotin is the coenzyme of compound enzymes. Biotin enzymes are essential in the synthesis of fatty acids and the resynthesis of carbohydrates — gluconeogenesis. It is also needed in the catabolism of amino acids.
Absorption, storage and excretion
Biotin is absorbed from the upper part of the sodium-dependent small intestine, and the amount of biotin absorbed by diffusion increases, when the quantities of biotin in the organism are larger. Only 8–15% of the biotin produced by the intestinal microflora is absorbed in the organism. It must be kept in mind that absorption is inhibited by excessive alcohol, tannin (tanning substance in tea), antibiotics and avidin (protein in the in raw chicken egg whites).
Vitamin H is stored in liver, kidneys and brain, and the reserves last for 2–7 week
Problems resulting from deficiency
- Loss of appetite
- Muscular pain
- Dry skin
- Seborrheic skin (very oily skin)
- Reduced level of hemoglobin
Risk groups for developing the deficiency
- People with ascetic lifestyle
- Pregnant women
- Excessive consumers of raw eggs
- Consumers of oral antibiotics
Use of vitamin preparations
May be used as an additional treatment component for treating alcoholism, depression, diabetes, dermatitis, eczema and muscular pain.
Studies have shown the stabilising function of the biotin genome, which reduces the risk of cancer. For instant, study results have indicated a slight biotin deficiency during the first trimester of pregnancy, which may be teratogenic due to the instability of the genome, therefore, pregnant women should take 600 µg biotin a day.
Figure 1. Vitamin B7: biotin
Vitamin B7 content in food
Quantities of food products which should be consumed daily to obtain the recommended daily amount of vitamin B7.
|Liver||63 g||81 g||130 g||137 g||156 g||167 g||167 g|
|Whole grain bread||283 g||367 g||583 g||617 g||700 g||750 g||750 g|
|Yeast||28 g||37 g||58 g||62 g||70 g||75 g||75 g|
|Egg||85 g||110 g||175 g||185 g||210 g||225 g||225 g|
|Boiled soy beans||68 g||88 g||140 g||148 g||168 g||180 g||180 g|
|Tomato||1133 g||1467 g||2333 g||2467 g||2800 g||3000 g||3000 g|
|Liver||130 g||156 g||156 g|
|Whole grain bread||583 g||700 g||700 g|
|Yeast||58 g||70 g||70 g|
|Egg||175 g||210 g||210 g|
|Boiled soy beans||140 g||168 g||168 g|
|Tomato||2333 g||2800 g||2800 g|