The basics of dog nutrition – water-soluble vitamins

Vitamin B1 (Thiamin)
After being modified in the body, thiamine pyrophosphate is involved in the following processes: Carbohydrate Metabolism, neurotransmitter production of glucose derivatives, and lipid metabolism. Important for growing dogs, nursing bitches, and working dogs.
Sources: Wheat Germs (2.4 mg / 100 g).

Vitamin B2 (Riboflavin)
Vitamin B2 is required for a wide variety of cellular processes. It plays a key role in fluid transportation of the respiratory chain. Low temperatures (below 10° C), working dogs and nursing bitches ask for additional B2.
Sources: Pork liver (3.7 mg / 100 g), calf liver (3.6 mg / 100 g), beef liver (3.2 mg / 100 g).

Vitamin B3 (Niacin)
Niacin takes part in the hydrogen transmission, the metabolism of protein, carbohydrates and fat, and is crucial for the regeneration of skin, muscles, nerves and DNA. Growing dogs and nursing bitches as well as dogs fed mainly with maize/corn-based food, ask for an increased intake.
Sources: Sheep liver (17 mg / 100 g), calf liver (15 mg / 100 g), beef liver (15 mg / 100 g).

Vitamin B5 (Pantothenic acid)
Dogs require pantothenic acid to synthesize coenzyme-A, as well as to synthesize and metabolize proteins, carbohydrates and fats.
Sources: Calf liver (7.9 mg / 100 g), beef liver (7.3 mg / 100 g), raw egg yolk (3.7 mg / 100 g).

Vitamin B6 (Pyridoxine)
Vitamin B6 is crucial for the metabolism of amino acids and proteins. A lack of this vitamin may lead to Hyperoxaluria, calcium oxalate kidney stones.
Sources: Lobster (1.20 mg / 100 g), salmon (0.98 mg / 100 g), sardine (0.96 mg / 100 g), chicken liver (0.80 mg / 100 g), pheasant (0.66 mg / 100 g).

Vitamin B7 (Biotin, Vitamin H)
While relevant for the metabolism of carbohydrates and fat, it is very important for the metabolism of protein. Growing dogs, nursing bitches, dogs with skin problems and dogs that are fed raw egg whites ask for additional B7.
Sources: Beef liver (100 mcg / 100 g), boiled egg (90 mcg / 100 g), calf liver (50 mcg / 100 g).

Vitamin B9 (Folic Acid, Vitamin M)
The dog needs folate to synthesize DNA, repair DNA, and methylate DNA as well as to act as a cofactor in certain biological reactions. A healthy dog does not need B9 supplements as microorganisms in the intestines synthesize significant amounts. Only nursing bitches ask for an increase.
Sources: Beef liver (590 mcg / 100 g), wheat germs (520 mcg / 100 g), calf liver (500 mcg / 100 g).

Vitamin B12 (Cobalamin)
It is important for the cell division, the formation of blood and the function of the nervous system.
Sources: Beef liver (100 mcg / 100 g), sheep liver (75 mcg / 100 g), calf liver (50 mcg / 100 g).

Vitamin C (Ascorbic acid)
There is no need for a vitamin C supplement as the dog synthesizes sufficient amounts of it in his liver and kidney. Even experiments, where vitamin C was supplemented to avoid conditions on the skeleton (e. g. HD) proved unsuccessful. Only after major surgery, serious burn wounds, liver diseases, or serious infections a supplement may be useful.
Sources: Acerola (1700 mg / 100 g), rose hip (1250 mg / 100 g), parsley (160 mg / 100 g).

Conclusion: If your vet told you that your dog needs a supplement of the Vitamin B group you may add 50 g of beef liver and one raw egg yolk per week as well as one table spoon of wheat germs per day to the usual food ration.