Which Vitamins Does Reverse Osmosis Remove?

Reverse osmosis is a common method of water purification. Mineral molecules are larger than water molecules, so they are left behind as water passes through the purification membrane. Vitamins are obtained from foods and are not present naturally in water, so there is no documentation that reverse osmosis systems remove any vitamins.

Commonly Known Minerals Removed

• Reverse osmosis systems originally appeared for desalination (salt removal) of seawater. It was discovered that not only sodium, but also iron, manganese and calcium could not seep through the membrane.

Controversial Additive Removed

• Those concerned with fluoride additives to municipal drinking water often buy reverse osmosis systems to treat their household water supply. This mineral's value for prevention of dental cavities versus risk of adverse effects is under scrutiny from public health activists.

Some Contaminants Removed

• Lead and chlorine stay behind the reverse osmosis membrane. If the RO system contains a carbon filter, it may remove some volatile organic compounds, pesticides and dioxins. Sulfates and nitrates, common in farmland water, can also be removed, as well as dissolved particulate matter.