Vitamin C is water-soluble, and probably the most famous of all the vitamins. Even before its discovery in 1932, physicians recognised that there must be a compound in citrus fruits preventing scurvy, a disease that killed as many as 2 million sailors between 1500 and 1800. Later researchers discovered that man, other primates and the guinea pig depend on external sources to cover their Vitamin C requirements. Most other animals are able to synthesise Vitamin C from glucose and galactose in their body. The most prominent role of Vitamin C is its immune stimulating effect, which is important for the defence against infections such as common colds. It also acts as an inhibitor of histamine, a compound that is released during allergic reactions. As a powerful antioxidant it can neutralise harmful free radicals and aids in neutralising pollutants and toxins. Thus it is able to prevent the formation of potentially carcinogenic nitrosamines in the stomach (due to consumption of nitrite-containing foods, such as smoked meat). Importantly, Vitamin C is also able to regenerate other antioxidants such as Vitamin E. Vitamin C is required for the synthesis of collagen, the intercellular 'cement' substance which gives structure to muscles, vascular tissues, bones, tendons and ligaments. Due to these functions Vitamin C, especially in combination with zinc, is important for the healing of wounds. Vitamin C contributes to the health of teeth and gums, preventing haemorrhaging and bleeding. It also improves the absorption of iron from the diet, and is needed for the metabolism of bile acids, which may have implications for blood cholesterol levels and gallstones. In addition, Vitamin C plays an important role in the synthesis of several important peptide hormones and neurotransmitters and carnitine. Finally, Vitamin C is also a crucial factor in the eye's ability to deal with oxidative stress, and can delay the progression of advanced age-related macular degeneration (AMD) and vision-loss in combination with other antioxidant vitamins and zinc.

Saha P, Pal RB, Das I, Sinha MK. Bilateral proptosis in a child with Vitamin C deficiency. 1. Int Ophthalmol. 2012 Jul 1. [Epub ahead of print]

Scurvy is one of the oldest diseases known to mankind, caused by Vitamin C deficiency. Nowadays it exists primarily in certain vulnerable populations such as patients with neurodevelopmental disabilities. Proptosis due to orbital haemorrhage is a rare complication of scurvy. Here we describe a case of diaplegic cerebral palsy presented with sudden onset of bilateral proptosis and swollen and tender knee joints. Subsequent computed tomography of the orbit revealed hematoma in the superior aspect of both orbits in the extraconal position. X-ray of the knee joints revealed bony changes consistent with scurvy. After 6?weeks of treatment with Vitamin C orally, the proptosis and the bony changes returned to normal. Although scurvy is a rare disease in the general pediatric population, it still exists in certain vulnerable populations like neurologically disabled ones, and this uncommon cause for proptosis should be considered in such children.