Drinking rainwater is often safe but you should filter it before drinking it as it could contain chemicals that it could collect from the air such as from pollution from cars, etc.
I have drank rainwater without filtering or boiling it before after it fell into a cup outside and didn't get sick but I would recommend boiling and or filtering the rain water before drinking it.
All water we drink is rainwater that filters into the ground and extracted from wells or collects in lakes etc and then is filtered and treated.
The cleanest water to drink is distilled water as distilled water is produced by boiling the water and then condensing the steam into pure water.
The process of distilling the water removes minerals, contaminants and impurities and makes it one of the purest forms of water to drink.
Spring water is also the best and cleanest water to drink and it's clean and contains minerals the body needs.
Well water that is free of contaminants is also healthy and clean to drink and also contains minerals and nutrients that the body requires to stay healthy.
The best water for kidneys is pure water without any chlorine or added chemicals.
You want to drink pure water that is filtered for your kidneys as chlorine and other chemicals in water can cause issues with kidneys.
Even water is filtered for kidney dialysis so you want to avoid chlorinated water when drinking it for kidney health and especially if you already have kidney failure you want to avoid chlorinated water and stick to bottled water or filtered water without chlorine or additional chemicals.
To keep your kidneys healthy you want to also avoid sweetened drinks, alcoholic drinks and caffeinated beverages.
As these drinks require more fluid to allow the body to properly process the toxins and chemicals that they contain and can stress the kidneys.
Pure water is the best for kidneys and doesn't stress the kidneys and is what the body really needs to stay healthy.
Pure and naturally filtered water is the best thing you can drink for good kidney health and you can also install water filters in your house to help keep the water healthier.
Also eating a well balanced diet of nutritious foods and low sodium foods that are packed with vitamins and the right minerals is the best way to keep your kidneys healthy and your overall health in check.
Eating the well balanced diet and low sodium foods and drinking pure water can help to stop or even slow the progression of kidney disease.