Vitamin / Mineral Supplements for Dogs
These dosages are recommended by Wendell Belfield, DVM in How to Have a Healthier Dog, Doubleday, 1981
Dog's Weight 20 pounds or less 20 to 50 pounds 50 to 100 pounds 100+ pounds
Vitamin A 1500 IU 3000 IU 5000 IU 7500 IU
Vitamin B1 0.5 mg 1 mg 2 mg 4 mg
Vitamin B2 0.5 mg 1 mg 2 mg 4 mg
Vitamin B3 15 mg 30 mg 50 mg 75 mg
Vitamin B6 0.75 mg 1.5 mg 3 mg 6 mg
Vitamin B12 6 mcg 15 mcg 30 mcg 45 mcg
Vitamin C 500 - 1500 mg 1500 - 3000 mg 3000 - 6000 mg 6000 - 7500 mg
Vitamin D 100 IU 200 IU 400 IU 400 IU
Vitamin E 100 IU 200 IU 200 IU 400 IU
Biotin 12 mcg 24 mcg 42 mcg 60 mcg
Calcium 15 mg 30 mg 50 mg 75 mg
Copper 1 mg 2 mg 3.5 mg 5 mg
Folic Acid 33 mvg 66 mcg 112 mcg 170 mcg
Iodine 0.2 mg 0.4 mg 0.7 mg 1 mg
Iron 9 mg 18 mg 30 mg 40 mg
Magnesium 10 mg 20 mg 50 mg 75 mg
Manganese 0.75 mg 1.5 mg 2.6 mg 3.75 mg
Pantothenic Acid 3 mg 6 mg 10 mg 15 mg
Phosphorus 11.5 mg 23 mg 40 mg 57 mg
Potassium 50 mg 100 mg 150 mg 200 mg
Selenium 12 mcg 25 mcg 50 mcg 50 mcg
Zinc 10 mg 10 mg 30 mg 30 mg
Nearly all supplement products intended for pets contain chemical preservatives. I suggest using multis intended for humans instead. Except for vitamins C and E, which can easily be given separately, a product called Centrum comes close to the right proportions for an adult Boxer, according to Belfield's recommendations. I buy a cheap supermarket copy for about half the price of the name brand.


In the morning, I give each of my Boxers a 200 iu vitamin E capsule and a 1000 milligram fish oil capsule. In the evening each of them gets a multiple vitamin/mineral tablet and a 1000 milligram flaxseed oil capsule. At each of their two daily meals, they get a generous 1000 milligram scoop of vitamin C, in the form of either sodium ascorbate or calcium ascorbate. That's a bit lower than Belfield's recommendation, but the additional vitamin C in the multiple vitamin tablet makes up the difference.

Belfield recommends using sodium ascorbate or calcium ascorbate rather than the more common form of vitamin C, ascorbic acid, because the acid form can produce diarrhea in some dogs. A mail order source for sodium ascorbate or calcium ascorbate is Bronson's, Box 46903, St. Louis, MO, 63146-6903, (800) 235-3200.