The Complete Guide to Supplements in Homemade Dog Diets

Home-prepared raw or cooked diets give you full control over ingredient quality and nutrient sourcing. Done right, they can provide species-appropriate nutrition far beyond what commercial dry foods offer. Ideally, dogs should obtain their vitamins and minerals from whole foods, primarily animal-based, with small amounts of well-prepared plant matter added when necessary.
But there are times when synthetic supplements are required. Limited ingredient variety, allergies, sourcing challenges, or therapeutic diets can all create gaps in nutrition. In these cases, understanding nutrient interactions, ratios, and bioavailability becomes critical. Supplementation without this awareness can unbalance the diet and undermine long-term health.

Zinc: Critical but easily unbalanced

Zinc supports immune function, skin integrity, and enzyme systems. Growing puppies and dogs with skin conditions often need higher levels.
  • Interactions: Zinc competes with copper, iron, calcium, and magnesium for absorption. The Zn:Cu ratio should hover near 10:1. Too much zinc can drive copper deficiency and reduce uptake of iron, magnesium, and calcium.
  • Supplement forms: Zinc oxide is poorly absorbed. Zinc picolinate, gluconate, or methionine are more bioavailable.
  • Whole-food sources, such as oysters, red meat (beef, lamb), pork organs, and egg yolks, provide zinc in its natural, balanced forms with cofactors that support absorption and metabolic use.

Calcium: Bones, balance and bioavailability

Home-prepared diets without raw meaty bones require added calcium.
  • Supplement forms: Calcium carbonate is cheap and common, but it needs strong stomach acid for absorption. In excess, it can act as an antacid, interfering with bone digestion (if bones are being fed) and mineral uptake. Calcium citrate is gentler but contains less elemental calcium.
  • Interactions: Excessive calcium can inhibit the absorption of zinc, iron and magnesium.
  • Whole-food sources: Raw meaty bones, human-grade bone meal, ground eggshell powder, sardines (with bones), and raw dairy products like kefir provide calcium along with phosphorus, magnesium, and vitamin K2, all of which are essential for proper bone mineralisation.

Antioxidants: Better in food than in pills

Antioxidants protect against oxidative stress, which is essential for working dogs, seniors, and individuals with chronic diseases. But in isolation, some vitamins act as pro-oxidants:
  • Example: Vitamin E requires vitamin C to regenerate. Without it, high doses of E can cause oxidative damage.
  • Whole-food synergy: Organ meats, oily fish, leafy greens, berries, and cruciferous vegetables provide a natural network of antioxidants and phytochemicals that work together.

Commercial dry food

Kibble doesn’t naturally contain the vitamins and minerals dogs need. The high-heat, high-pressure manufacturing process destroys most nutrients, so they must be added back later as synthetic premixes.
This includes trace minerals like copper. The problem is:
  • The form and bioavailability of these synthetics are often unclear.
  • Some nutrients, like copper, can accumulate in the liver over time. This is a particular risk in breeds such as the Bedlington Terrier, Doberman and Labrador.
Adding nutrient-dense treats, such as dehydrated liver, on top of kibble can increase copper and vitamin A intake to a dangerously high level.
In contrast, with a fresh food diet, you can:
  • Control copper and vitamin A levels precisely.
  • Use liver as the ideal natural source of these nutrients without the risk of stacking them on top of hidden synthetics.

Final thoughts

Meeting nutrient requirements in home-prepared diets is not just about hitting minimum numbers. The form, source and ratio matter.
  • Whole foods provide nutrients in their most bioavailable, synergistic form.
  • Synthetic supplements are sometimes necessary, but they should be chosen with care, ideally under the guidance of a qualified canine nutrition professional.
  • Puppies, breeding dogs and those with chronic conditions are especially sensitive to nutrient imbalances.
When in doubt, start with whole foods, supplement only where necessary and always prioritise balance over brute force.
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