Vitamins and Nutrition

Vitamin C (ascorbic acid) is found in high concentrations in citrus fruits like oranges, lemons, and grapefruits. Milk and eggs are poor sources of Vitamin C, and while some leafy greens have it, citrus is the primary dietary source.

Vitamin A is crucial for maintaining healthy vision, especially in low-light conditions. It helps form rhodopsin, a pigment in the retina responsible for night vision, and prevents eye conditions like xerophthalmia and night blindness.

Vitamin K is essential for blood clotting as it helps produce proteins required for coagulation, including prothrombin and clotting factors II, VII, IX, and X. Without Vitamin K, blood cannot clot properly, leading to excessive bleeding. The name comes from the German word 'Koagulation'. It's also produced by bacteria in our intestines.

Fat-soluble vitamins dissolve in fats and are stored in the body's fatty tissues and liver. The four fat-soluble vitamins are A, D, E, and K. Unlike water-soluble vitamins (B complex and C) which are excreted in urine, fat-soluble vitamins can accumulate to toxic levels.

Water-soluble vitamins dissolve in water and are not stored in the body - they must be consumed regularly as excess is excreted in urine. The B-complex vitamins (B1, B2, B3, B5, B6, B7, B9, B12) and vitamin C are water-soluble.

Vitamin A deficiency is a leading cause of preventable blindness in children, particularly night blindness (nyctalopia). Vitamin A is essential for the formation of rhodopsin, the pigment in rod cells that enables vision in low-light conditions. Deficiency also causes dry eyes (xerophthalmia) and can lead to complete blindness if untreated.

Apples are a good source of Vitamin C, with one medium apple providing about 8.4 mg (roughly 14% of daily value). While not as concentrated as citrus fruits, apples contain more Vitamin C than Vitamins E, B1, or K, which are either minimal or absent.

Oranges are famously rich in Vitamin C, with one medium orange providing over 100% of the daily recommended intake. Citrus fruits like oranges are one of nature's best Vitamin C sources, unlike Vitamins K, B12, or D which are minimal in oranges.

Grapes contain Vitamin C, though in modest amounts (about 3-4 mg per cup). While not as concentrated as citrus fruits, grapes do provide Vitamin C, unlike B9, B12, or B3 which are minimal in grape composition.

Bananas contain Vitamin C (approximately 8-10 mg per medium banana), though they're more famous for potassium. While not their primary nutrient, bananas do provide Vitamin C, unlike B9, B12, or D which are minimal or absent in significant amounts.

Kiwi fruits contain Vitamin A, though in smaller amounts compared to their exceptional Vitamin C content. While kiwis are not a primary Vitamin A source like carrots or liver, they do provide this fat-soluble vitamin that supports vision and immune function.

Lemons are excellent sources of Vitamin C, with one lemon providing about 53 mg (over half the daily requirement). As a citrus fruit, lemons are renowned for their Vitamin C content, unlike Vitamins K, B12, or D which are minimal in lemons.