You're right to be concerned about what dog vitamins you should be giving your best friend. Just like people benefit from vitamins and supplements, dogs also benefit from good nutrition.
We couldn't possibly make a specific recommendation for your dog, only a vet could do that. But we will cover dog vitamins in general to allow you to see how they would benefit your pet and allow you to talk more with your vet about caring for this important member of your family.
Dogs need the following dog vitamins:
Vitamin A - helps dryness, hardening and itching of the skin. Also protects against infection and toxic chemicals.
Vitamin C - helps to fight scurvy, less likely to develop hip dysplasia, spinal myelopathy, ruptured discs, viral disease, skin problem and common bacterial infections.
Vitamin B1 - Thiamine - helps dogs become more alert and intelligent, also helps with fleas and other parasites (they don't like it).
Vitamin B2 - Riboflavin - helps protein and fat metabolism; also helps prevent cataracts in the eyes.
Vitamin B3 - helps convert food to energy, helps protein and fat metabolism. Also controls convulsive seizures in dogs.
Vitamin B5 - Pantothenic Acid - is an anti-stress vitamin because it's required for producing good antibodies, helps longevity. Dogs deficient in Vitamin B5 can't fight infection.
Vitamin B9 - Folic Acid - Dogs need folic acid during pregnancy and to help build the immune system. Signs of deficiency in dogs include: erratic appetite, retarded weight gain, watery secretion from the eyes, and decreased antibody response to microorganisms.
Vitamin B12 - For pregnant dogs studies have shown vitamin B12 may help in building stronger bigger pups capable of handling stress. Puppies need minuscule amounts to stimulate appetite, weight gain and growth.
Vitamin D - key in calcium and phosphorus metabolism to help with strong bones and teeth. Sunlight stimulates dogs to generate vitamin D.
Vitamin E - helps boost the efficiency of the heart and circulation system. Promotes dilation of the small blood vessels, increasing the supply of oxygen to all of the body. Vitamin E helps to improve your dogs immune system, muscle power, and stamina. It also protects against air pollution and has been know to rejuvenate ailing and tired dogs.
Vitamin H - Biotin - helps reduce the incidence of skin disorders. Assists the thyroid and adrenal glands and aids the nervous system. Also helps in the prevention of coprophagy (the animal eating its own excrement).
These are essential dog vitamins. It's best you consult with your vet on specific issues for your dog's vitamin needs.
What you can do is feed your dog a food and vitamin supplement that have dog vitamins scientifically blended in it, here's an great product with a free trial: