Dogs need 13 essential vitamins in their diet, and homemade meals almost never provide all of them without supplementation. A review of 200 homemade dog food recipes found that 95% fell short of established nutritional guidelines for at least one essential nutrient, with 83.5% having multiple deficiencies. The most commonly missing nutrients were zinc, choline, vitamin D, vitamin B12, and vitamin E. Understanding what each vitamin does and where to find it will help you build meals that actually nourish your dog.
Fat-Soluble Vitamins: A, D, E, and K
Fat-soluble vitamins dissolve in fat and get stored in your dog’s body, which means they build up over time. This makes them both essential and potentially dangerous if you overshoot the amounts. AAFCO sets minimum and maximum thresholds for these vitamins per 1,000 calories of food.
Vitamin A supports vision, immune function, and skin health. Your dog needs a minimum of 1,250 IU per 1,000 calories, but toxicity starts well before the upper limit of 62,500 IU. Liver is the richest whole food source, followed by fish oil, eggs, and dairy. Because liver is so concentrated in vitamin A, feeding it daily without measuring portions can push your dog into excess territory. A few ounces per week is typically enough for a medium-sized dog, but the exact amount depends on the rest of the diet.
Vitamin D regulates how your dog absorbs calcium and phosphorus, making it critical for bone health. Dogs can’t produce vitamin D from sunlight the way humans do, so every bit has to come from food. The minimum requirement is 125 IU per 1,000 calories, with a maximum of 750 IU. Fatty fish, fish oil, egg yolks, and beef liver are the best whole food sources. Vitamin D is one of the nutrients most frequently deficient in homemade diets, and it’s also one of the most dangerous in excess. Clinical signs of toxicity, including dangerously high calcium levels and organ damage, can appear at surprisingly low doses.
Vitamin E acts as an antioxidant, protecting cells from damage. The minimum is 12.5 IU per 1,000 calories, and dogs eating diets high in polyunsaturated fats (like those containing fish oil or vegetable oils) need proportionally more. Vegetable oils, seeds, and whole grains provide vitamin E naturally, but most homemade diets still come up short without a supplement.
Vitamin K supports blood clotting. Green leafy vegetables, liver, and fish are good sources. Deficiency is less common because gut bacteria produce some vitamin K on their own, but it still needs to be part of the overall diet.
B Vitamins and Choline
Dogs require eight B vitamins plus choline, and because these are water-soluble, your dog’s body doesn’t store them efficiently. They need to be replenished through food regularly.
Here’s where each one comes from in whole foods:
- B1 (thiamin): whole grains, organ meats, egg yolk
- B2 (riboflavin): dairy, organ meats, muscle meats, eggs
- B3 (niacin): fish, yeast, cereals, legumes
- B5 (pantothenic acid): liver, heart, rice bran, fish
- B6 (pyridoxine): meats, whole grains, vegetables
- B7 (biotin): egg yolks, liver, oilseeds
- B9 (folic acid): liver, egg yolks, green vegetables
- B12 (cobalamin): organ meats, fish, dairy
Choline functions differently from the other B vitamins. It supports liver detoxification and serves as a building block for key nervous system chemicals that control muscle movement and mood. Egg yolks are the single best whole food source, followed by organ meats, fish, and legumes. Choline is one of the five nutrients most likely to be deficient in homemade dog food, so it deserves special attention when planning recipes.
A pattern emerges across the B vitamins: organ meats (especially liver and heart), eggs, and fish appear repeatedly. If your homemade diet is built primarily around muscle meat like chicken breast or ground beef, you’re likely missing several B vitamins. Including organ meats at roughly 10% to 15% of the total meat portion covers a lot of ground, though it still won’t fill every gap on its own.
Calcium, Phosphorus, and Why They Matter Here
Vitamins don’t work in isolation, and vitamin D’s role is a perfect example. Vitamin D controls how your dog absorbs calcium and phosphorus, so even if you nail the vitamin D amount, an imbalanced calcium-to-phosphorus ratio can cause skeletal problems. The recommended ratio is between 1:1 and 2:1 (calcium to phosphorus). Meat is naturally high in phosphorus and low in calcium, so homemade diets built around meat almost always need a calcium source added, whether that’s ground eggshell, bone meal, or a supplement.
This is especially critical for growing puppies and large breeds. An excess or deficiency of either mineral during development can contribute to serious orthopedic conditions.
Why Whole Foods Alone Usually Fall Short
Even a varied, thoughtfully constructed homemade diet tends to have nutritional gaps. The challenge isn’t that whole foods lack vitamins. It’s that hitting every single requirement in the right proportions, day after day, is extremely difficult without supplementation. Vitamin E, vitamin D, choline, and B12 are the most persistent shortfalls.
Not all pet supplements are designed for this problem. The supplement market splits into two categories: low-dose multivitamins meant to top off a commercial diet that’s already complete, and higher-dose formulations specifically designed to fill the gaps in homemade meals. Only a few products fall into that second category. Using a standard pet multivitamin on top of a homemade diet likely won’t correct the deficiencies, because those products assume most nutrients are already present in the kibble or canned food.
If you’re using a supplement formulated for homemade diets, timing matters. Add it right before serving rather than mixing it into food during or after cooking. Heat degrades water-soluble vitamins, particularly the B vitamins, so cooking the supplement into the food reduces its effectiveness.
Putting It All Together
A well-rounded homemade dog diet typically includes muscle meat, organ meat (liver and heart especially), a calcium source, a starchy carbohydrate, vegetables, and a fat source like fish oil. That combination covers many vitamins naturally. Liver alone provides vitamins A, D, several B vitamins, and choline. Eggs add biotin, riboflavin, choline, and fat-soluble vitamins. Fish or fish oil contributes vitamin D and essential fatty acids. Green vegetables supply vitamin K and folic acid.
But “covers many” is not the same as “covers all.” The nutrients that consistently remain below recommended levels in homemade recipes, even well-designed ones, are vitamin D, vitamin E, choline, B12, and zinc. A homemade-diet-specific supplement or a recipe formulated by a veterinary nutritionist closes those gaps. Services like Balance IT generate recipes that pair specific ingredients with a matched supplement, and while no tool is perfect, using one is measurably better than guessing.