"The Coconut Board of India reports the numerous medicinal properties of tender coconut water as:"

• Good for feeding infants suffering from intestinal disturbances.
• Oral rehydration medium
• Contains organic compounds possessing growth promoting properties
• Keeps the body cool
• Application on the body prevents prickly heat and summer boils and subsides the rashes caused by small pox, chicken pox, measles, etc.
• Kills intestinal worms
• Presence of saline and albumen makes it a good drink in cholera cases
• Checks urinary infections.
• Excellent tonic for the old and sick
• Cures malnourishment.
• Diuretic
• Effective in the treatment of kidney and urethral stones
• Found as blood plasma substitute because it is sterile, does not produce heat, does not destroy red blood cells and is readily accepted by the body.
• Aids the quick absorption of the drugs and makes their peak concentration in the blood easier by its electrolytic effect.
• Urinary antiseptic and eliminates poisons in case of mineral poisoning.
  

Source: http://coconutboard.nic.in/tendnutr.htm

Coconut Juice:

It's a natural isotonic beverage with the same level of electrolytic balance as we have in our blood. It's the fluid of life, so to speak, says Mr. Morton Satin, Chief of FAO's Agricultural Industries and Post Harvest Management Service.

The US Department of Agriculture (USDA) reports that one serving of coconut juice can provide a person his Vitamin C requirements for the day. Below is a list of the food value of coconut juice based on USDA findings.