What nutrient deficiency causes night blindness?

Night blindness—commonly known as “sparrow blindness”—causes difficulty or inability to see in dim light or at night. So, what nutrient deficiency causes night blindness?

What nutrients are deficient in night blindness?

Night blindness is primarily caused by vitamin A deficiency, with children under four years of age being at higher risk. Vitamin A and beta-carotene do not readily cross the placenta for fetal absorption and utilization; thus, newborns have low endogenous vitamin A stores and are prone to deficiency if timely supplementation is not provided—potentially leading to night blindness. Inappropriate dietary habits can also impair vitamin A absorption. As vitamin A is a fat-soluble vitamin, insufficient dietary fat intake—or conditions affecting the liver, gallbladder, or pancreas—can hinder its digestion and absorption. Certain diseases may increase vitamin A consumption and deplete its bodily reserves.

Night blindness results from inadequate vitamin A. Vitamin A is obtained from two main dietary sources: first, preformed vitamin A (retinol) found directly in animal-derived foods—such as liver, egg yolk, butter, and other animal offal; second, provitamin A carotenoids (especially beta-carotene) abundant in yellow-green vegetables and fruits—including carrots, Chinese cabbage, chili peppers, tomatoes, and oranges.

Upon diagnosis of night blindness, serum vitamin A levels can be assessed, and vitamin A supplementation initiated promptly. Consuming a variety of vitamin A–rich foods is also recommended. We hope this information proves helpful to you!