Urtica dioica traces of zeaxanthin or between 20 – 60 mg / kg of dry matter. Nettle contains ascorbic acid (vitamin C), riboflavin (vitamin B), pantothenic acid, vitamin K and tocopherols (vitamin E). The highest vitamin contents can be found in the leaves. In laying hens, nettle can be used as an egg yolk colorant instead of artificial pigments or other natural pigments (derived from marigold for yellow). Nettle has high carotenoid contents, especially lutein, β-carotene and zeaxanthin, of which lutein and zeaxanthin act as yellow pigments. Feeding as little as 6.25 g dry nettle per kg feed is as effective as
Vitamin B6 4-pyridoxic acid. Several studies have shown that 4-pyridoxic acid is undetectable in the urine of vitamin B-deficient subjects, making it a useful clinical marker to assess the vitamin B status of an individual. Other products of vitamin B metabolism excreted in the urine when high doses of the vitamin have been given include pyridoxal, pyridoxamine, and pyridoxine and their phosphates. A small amount of vitamin B is also excreted in the feces. The classic clinical syndrome for vitamin B deficiency is a seborrhoeic dermatitis-like eruption, atrophic glossitis with ulceration, angular cheilitis, conjunctivitis, intertrigo, and neurologic symptoms of somnolence, confusion, and