For females this would usually be finished in about 1 hour 15minutes. For males this would be finished in about 1 hour. Olympic distance triathlon (1500m / 40m bike / 10km run) For females this would take about 2 hours 25mins. For males this would take about 2 hours. Half Ironman (1.9km swim / 90km bike / 21km run) Females usually take about 5 hours 30mins.
Zinc. Night blindness may also be the result of a zinc deficiency which reduces the activity of an enzyme that helps the body produce vitamin A (retinol dehydrogenase). Research has shown that taking a zinc supplement is helpful. Healthcare providers often recommend 15 - 30 mg of zinc daily for vision.
Vitamin D and Its Effects on Eyesight. An eye doctor trying glasses on a patient. It has been estimated that the complex system that enables eyesight requires about 30 percent of a personâs oxygen intake and 25 percent of their nutritional intake. Thus, healthy eyesight depends on essential nutrients, such as vitamins. Vitamins A, C and E are antioxidants that have been well-established as preserving eyesight and promoting healthy eyes, but evidence suggests vitamin D is associated with reduced risks of macular degeneration.