Vitamins in the Life of Fish.
What are vitamins? The name comes from a combination of the words “Vita” (life) and “Amin” (indicating a chemical compound). Vitamins are vital organic substances that cannot be synthesized (meaning produced) by a living organism and therefore must be obtained through food. While mineral salts can be present in sufficient quantities in water and substrate (under optimal keeping conditions), all other components are received by fish only with food, both of animal and plant origin.
One of the main conditions for the normal growth, development, and reproduction of aquarium fish is proper and balanced nutrition. The food composition must include proteins, fats, carbohydrates, as well as minerals and vitamins. For healthy growth and magnificent coloration, decorative fish need food that meets their needs for nutrients, vitamins, and minerals in the necessary proportions. The content of fats and vitamins in the fish’s body must be in the correct ratio so that the organism can burn fats efficiently. Therefore, the food should be low in fat (below 6%).
Vitamins is a single term for completely diverse substances. Accordingly, the action of various vitamins is very diverse, and the need for these vitamins varies greatly. They are involved in almost all biochemical and physiological processes that make up metabolism as a whole. Vitamins are required by organisms in very small quantities. Water-soluble and fat-soluble vitamins are distinguished. In addition, a group of vitamin-like compounds is distinguished.
Water-soluble ones include: ascorbic acid (vitamin C), B group vitamins – thiamine, riboflavin, (cobalamin), niacin (vitamin PP), folacin, pantothenic acid, biotin — they are soluble in water and can be added as special supplements. Vitamins such as A, D, E,
K are insoluble in water (they dissolve in oil) and therefore must be added together with food. The lack of one vitamin cannot be compensated by another. The absence of any vitamin leads to slowed growth, a weakened immune system, etc. Some food components contain vitamins, but usually, they are added as additional components. This is especially important for aquarium fish that do not receive live food and do not supplement their menu with plant-based food.
Water-Soluble Vitamins:
Vitamin B1 – (thiamine, aneurin), necessary for obtaining energy from food carbohydrates, as well as for supplying the brain and nervous system with sugar as the basis of their nutrition. Necessary for the growth of fish, especially fry. A deficiency of this vitamin leads to impaired motor function and, ultimately, convulsions. The main sources of Vitamin B1 are: mollusks, diatoms, lettuce, yeast, egg yolk, peas, raw meat.
Vitamin B2 – (riboflavin), plays an important role in building muscle tissue and protecting the mucous membrane of the skin. A shortage of this vitamin can cause a symptom of mineral starvation, manifested in skin hemorrhages and nervous system disorders. The main sources of Vitamin B2 are: copepods and cladocerans, fish, mollusks, beef liver and heart, egg yolk, peas, lettuce, yeast.
Vitamin B5 – (Vitamin PP), necessary for hormone production in the body and normal metabolism. Plays an important role in the formation of various enzymes. A deficiency of this vitamin causes a symptom of mineral starvation, manifested in gill damage. The main sources of Vitamin B5 are: vegetables, yeast, beef liver.
Vitamin B6 – (pyridoxine), very important for the nervous system, necessary for normal metabolism. A deficiency of this vitamin leads to nervous system disorders manifested in impaired motor function. The main sources of Vitamin B6 are: copepods and cladocerans, fish, mollusks, beef liver and heart, egg yolk, lettuce, yeast, milk, and bran.
Vitamin B12 – (cyanocobalamin), necessary for the normal functioning of digestive organs and for the formation of hemoglobin, which is so necessary for oxygen transport. A shortage of this vitamin leads to anemia, the consequence of which is apathy and slowed growth. The main sources of Vitamin B12 are: fish, mollusks, fishmeal, meat, egg yolk.
Vitamin C – (ascorbic acid), necessary for normal carbohydrate and energy metabolism. A crucial component for skeleton building. In addition, it plays a decisive role in strengthening the body’s defenses. A deficiency of this vitamin leads to gill deformation, reduced immunity, and, accordingly, predisposition to diseases. The main sources of Vitamin C are: fish roe, aquatic plants, green algae, lettuce, beef liver.
Vitamin H – (biotin), a crucial growth factor. A deficiency of this vitamin leads to slowed growth (development), as well as loss of appetite and convulsions. The main sources of Vitamin H are: fish, beef liver and kidneys, dairy products, egg yolk.
Fat-Soluble Vitamins:
Vitamin A – improves vision and promotes healthy development, necessary for normal growth. In addition, it protects the skin and activates reproduction. A deficiency of this vitamin leads to eye damage and skin hemorrhages, sometimes malformations. The main sources of Vitamin A are: copepods and cladocerans, green algae, fish liver, egg yolk.
Vitamin D3 – regulates the intake of calcium and phosphorus and is especially important for bone and skeletal growth. A shortage of this vitamin leads to bone deformation (rickets), spinal curvature, emaciation, sunken belly. The main sources of Vitamin D3 are: cladocerans, mollusks, fish liver, earthworms, egg yolk.
Vitamin E – promotes the formation of reproductive hormones, necessary for the normal development of sex organs and reproduction. In addition, it stabilizes other vitamins in the feed, as well as fatty acids. If deficient, fish are accordingly incapable of reproduction. The main sources of Vitamin E are: green algae, lettuce, egg yolk.
Vitamin K – (phylloquinone), necessary for growth and proper blood formation, promotes blood clotting after various injuries. A deficiency of this vitamin leads to impaired healing processes and liver damage. The main sources of Vitamin K are: cladocerans, lettuce, spinach, dandelion and nettle leaves, beef liver.
Choline – (cholin), promotes easier digestion and absorption of fat. A shortage of this vitamin leads to fatty liver disease and fatty degeneration of other vital organs, including those responsible for reproduction.
Vitamins are absolutely essential for fish; otherwise, they may develop “avitaminosis” — a disease arising as a consequence of insufficient vitamin supply. The industry 
manufacturing food for our fish has developed delicious and healthy mixtures. Of course, these include vitamin supplements. However, many vitamins are volatile substances and are not suitable for long-term storage. In nature, a diverse diet guarantees a sufficient amount of minerals, vitamins, and trace elements. Providing the same composition of essential substances in standard factory-packaged food is hardly possible precisely because of their limited shelf life, and that is why manufacturers increasingly offer trace elements and vitamin preparations packaged separately.
It is recommended to store vitamins only in the refrigerator. Another very important aspect: these supplements can and should be used only before turning off the aquarium lighting. Light destroys vitamins! In Germany, experienced aquarists buy a vitamin concentrate for all pets, which can also be used for fish. This concentrate is sold in pharmacies and is not very expensive, considering that fish need one drop of concentrate per 2 liters of aquarium water daily. The concentrate is produced by Lohmann animal Health GmbH & Co KG and is called AD3E-TAD. Overdose of the preparation is harmless to fish in most cases.
Vitamin supplementation should be combined with preparations containing no impurities. It is best to dissolve them in distilled water (if not done in advance by the manufacturer). In aquarium hobby, it is customary to add vitamins to fish food. Live food, such as red bloodworms and other species, is particularly suitable for this. Before feeding, bloodworm larvae should be sprayed with the vitamin preparation so that the liquid can settle on them. If the preparation is mixed into a solution containing vegetable oil or sugar, the live food should be sprayed with it in minimal quantities: the larvae or midges might suffocate. For vitamin supplementation combined with dry food, basically the same methods are used: spraying or mixing.
Fish should not be fed the day before. The faster they devour the food sprayed with the preparation, the faster the vitamins reach their stomachs. But if the vitaminized food is left lying in the aquarium for a long time, the vitamins will, of course, dissolve in the water. Sometimes authors of aquarium articles suggest adding vitamin preparations directly to the aquarium water. But this method is inefficient and insufficiently effective. After all, the necessary substances turn out to be diluted too much, fish do not know how to filter water, and therefore are unable to absorb these substances in full.
Vitamins come predominantly with food (crustaceans are highest in vitamins). The daily requirement for vitamins looks approximately like this (per 1 kg of fish weight): retinol (A) — 100-500 mg, thiamine (B1) — 0.15 mg, riboflavin (B2) — 0.11-0.33 mg, pantothenic acid (B3) — 0.1-1.4 mg, nicotinamide — 0.55 mg, etc. If it is not possible to feed fish live food, vitaminized fish oil or oil-based vitamin D should be added to dry food (1-3 drops per matchbox). The food must be fed within 2-3 days. It is stored in the refrigerator for no more than 3 days. Antioxidants must be added to store-bought dry foods to prevent feed rancidity. The immunity of your pets can be increased by using vitaminized feeds or special vitamin complexes for aquarium fish.
Cichlids must receive nutritious food rich in vitamins. If there is a deficiency of vitamins in the fish’s body, they will begin to make up for the shortage by nibbling on higher vegetation, causing the latter to acquire a very unsightly appearance. Cichlids can be provided with vitamins by feeding them vegetarian components – lettuce, pumpkin, carrots, bell peppers, zucchini, nettles, dandelions, and a number of other plant supplements sold year-round, including specialized branded ones available in pet stores. In general, vegetation in an aquarium with cichlids is simply necessary, as fish constantly need vitamins and trace elements. The best guarantee of meeting this need is aquatic plants.
It is simply amazing how many people in the world strictly follow a diet and regularly reinforce their health with vitamins, while at the same time giving their fish only prepared food of a single type. Every fish species needs specific food.
Minerals and trace elements needed by fish.
Feed additives to enhance the pigmentation of fish and shrimp. 
