Dairy cow vitamin A (A), D3 (D3) and E (E) supplementation increased 45, 36, and 107%, respectively, in the last 18 years, while milk production/cow increased by 30%. The objective of this trial was to evaluate the effect of vitamin A supplementation reduction on productive and repproductive performance. A total of 380 Holstein cows were used in a randomized complete block design with cow as the experimental unit, treatment as the fixed effect, and block as the random effect (190 cows × 2 treatments). Cows was pre-tested for the level of A and E required to maintain the neutrophil function level (using neutrophil phagocytosis test measured by phagocytosis assay, Phagotest^R), which was 2,125 IU E and 185,236 IU A/cow/day (adjusted to 658 kg cow BW). Treatments were positive control (PC) supplemented with 2,125 IU E and 185,236 IU A/cow/day to maintain neutrophil function level (dry and lactating) and 1.5× for fresh cows (277,854 IU/H/day) and a negative control (NC) group with 60% reduction of A (75,000 IU/H/day) for dry and milking cows, and 1.5× for fresh cows (112,500 IU/H/day), while maintaining the E at the same level 2,125 IU/H/day for dry and lactating cows and 3,000 IU/H/day for fresh cows. These levels of supplementation were maintained for 36 mo. Cows were blocked by age and milk production/cow/day and fed corn/corn silage diets formulated to meet or exceed 2001 NRC recommendations, except for A and E. The first 6-mo showed no significant difference between the 2 treatments. Neutrophil phagocytosis % (98 and 99, P = 0.50, respectively); days open (115 and 117, P = 0.45, respectively) and number of lactations/cow (4.2 and 4.1, P = 0.25, respectively). After 36 mo, the NC showed a 24% significant decrease in neutrophil phagocytosis (99, 75%, P = 0.03, respectively); a 26% significant increase in days open (112 and 154, P = 0.03, respectively); and a 28% significant decrease in number of lactations/cow (4.3 and 3.1, P = 0.02, respectively). In conclusion, vitamin A may be substantially reduced for several months. However, long-term vitamin A reduction leads to significant reductions in productive and reproductive performance.