What are the chances of your crew suffering scurvy? If you live in the Western World it is most unlikely. Why? Because many of the fresh foods we eat contain vitamin C (ascorbic acid).
Scurvy does not occur in most animals because they can synthesize their own vitamin C, but guinea pigs, primates (including humans) lack an enzyme necessary for such synthesis - they must obtain vitamin C through their diet. This vitamin is widespread in plant tissues, with particularly high concentrations occurring in citrus fruits such as oranges, lemons, limes and grapefruit, but it is also present in tomatoes, potatoes, cabbages, and green peppers.
Foods containing vitamin B also help prevent scurvy. A regular intake of both vitamins C and B will ensure a person does not suffer from this serious disease that was rampant among 18th century sailors, particularly those who spent months at sea while sailing the oceans of the world. A diet deficient of vitamin C for six months will ensure the onset of scurvy.
For a graphic account of its effects, here is an edited quote from a BBC Discovery web page:
“Scurvy came to public notice in Britain after Commodore George Anson led a squadron into the Pacific in the 1740s to raid Spanish shipping. He lost all but one of his six ships, and two thirds of the crews he shipped (700 survived out of an original complement of 2000), most of them to scurvy. Their symptoms were vividly described by Richard Walter, the chaplain who wrote up the official account of the voyage. Here were descriptions of its ghastly traces: skin black as ink, ulcers, difficult respiration, teeth falling out and, perhaps most revolting of all, a strange plethora of gum tissue sprouting out of the mouth, which immediately rotted and lent the victim's breath an abominable odour.”
“There were strange sensory and psychological effects too. Scurvy seems to have disarmed the sensory inhibitors that keep taste, smell and hearing under control. When sufferers got hold of the fruit they had been craving they swallowed it (said Walter) 'with emotions of the most voluptuous luxury'. The sound of a gunshot was enough to kill a man in the last stages of scurvy, while the smell of blossoms from the shore could cause him to cry out in agony. This susceptibility of the senses was accompanied by a disposition to cry at the slightest disappointment, and to yearn hopelessly and passionately for home.”
Another source quoting historical facts had this to say:
“Vasco da Gama lost two thirds of his crew to the disease while making his way to India in 1499. In 1520 Magellan lost more than 80 per cent while crossing the Pacific. Two voyages made by Pedro de Quiros early in the 17th century resulted in huge mortality from a sickness Sir Richard Hawkins called, after his venture into the South Seas, 'the plague of the Sea, and the Spoyle of Mariners'.”
“In 1747 the Scottish naval surgeon James Lind treated scurvy-ridden sailors with lemons and oranges and obtained dramatic cures. In 1795 the British navy began to distribute regular rations of lime juice during long sea voyages (hence the name limeys for British sailors), a measure that was largely successful in preventing scurvy. It was probably the first disease to be definitely associated with a dietary deficiency.”
My advice for those intent on blue water cruising would be to take with them fresh vitamin C bearing vegetables and fruit to last as long as they remain palatable, then swap to dehydrated vegetables from a source such as Walton Feed, whose web page can be found at http://waltonfeed.com/self/deh-veg.html. It is possible to make your own dehydrated food - see http://www.budget101.com/dehydrated_foods.htm. Also make sure you have a supply of vitamin C and B supplements.