Vitamin A is essential for your dog's vision, immune function, skin health, and reproductive performance. It maintains the integrity of epithelial tissues — the cells lining the skin, respiratory tract, digestive tract, and urinary tract — which serve as the body's first line of defense against infection. In the eye, vitamin A is a component of rhodopsin, the light-sensitive pigment in the retina that enables vision in low light. Dogs can convert beta-carotene from plant sources into active vitamin A (retinol), unlike cats who cannot — but preformed vitamin A from animal sources (liver, eggs, fish oil) is more efficiently used. Vitamin A also supports proper cell differentiation, which is why it is critical during growth and pregnancy. This is a fat-soluble vitamin that the body stores in the liver, which means both deficiency and excess develop slowly and can accumulate over time.
A small piece of sweet potato about the size of your thumb provides roughly 400–500 IU of vitamin A (as beta-carotene) — a medium adult dog needs approximately 1,262–5,000 IU of vitamin A per day. Liver is the richest source but should be fed sparingly (no more than 5% of the total diet) to avoid toxicity. Sweet potato, carrots, pumpkin, and eggs are safer everyday sources that provide vitamin A without the risk of excess.
0.0% of daily nutrient intake
Vitamin A makes up 0.0% of your dog's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Night blindness and poor vision in dim light, dry or cloudy eyes, rough dry coat, thickened flaky skin, increased susceptibility to respiratory and skin infections, poor growth in puppies, and reproductive failure in breeding dogs. Severe deficiency can lead to corneal ulceration and permanent vision damage.
Vitamin A toxicity (hypervitaminosis A) is a real risk because it accumulates in the liver. Chronic excess causes bone and joint pain, stiff neck, lameness, weight loss, and in severe cases, liver damage. Feeding liver excessively is the most common dietary cause — it is an incredibly concentrated source. Symptoms develop gradually over weeks to months of excessive intake.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | medium 10-25kg | 1262 | 5000 | IU | NRC recommended allowance for a medium adult dog. Do not exceed upper limit due to liver accumulation. |
| Juvenile | — | 1262 | 2500 | IU | Puppies need vitamin A for growth, vision development, and immune function. Most puppy foods provide adequate levels. |
| Pregnant / Nursing | — | 1500 | 6250 | IU | Pregnant dogs need more vitamin A for fetal development, but excess can cause birth defects. Follow veterinary guidance. |
| Senior | medium 10-25kg | 1262 | 5000 | IU | Senior dogs maintain similar vitamin A needs. Liver stores accumulate over a lifetime, so avoid excessive supplementation. |
Source: NRC 2006
Vitamins A and D share absorption pathways and interact at the cellular level. Very high vitamin A intake can interfere with vitamin D's functions, and vice versa. Both are fat-soluble and accumulate in the liver.
What this means: Avoid over-supplementing either vitamin A or D in isolation. Liver is extremely rich in vitamin A and should be fed sparingly (no more than 5% of diet). If supplementing one of these vitamins, ensure the other is also adequate.
