It’s that time of year again, the suns out, we’re lathered with sunscreen, craving ice lollies and my 2 year old son has to have liquid salt twice a day. (which is for some reason a nightmare to get hold of from our G.P…but that’s another story)
Children and adults with Cystic Fibrosis require sodium (salt) supplementation in the hot weather due to salt loss. This extra salt can come from eating salty foods like chips with extra salt, sauces, dips and crisps or is often prescribed in the form of sodium tablets or sodium chloride solution.
Joe has to have 1.6ml of Sodium Chloride 30% solution- 5mmol/ml twice a day during the hot weather to prevent excessive salt loss.
So why is this the case?
People with cystic fibrosis inherit a defective gene on chromosome 7 called the CFTR (cystic fibrosis transmembrane conductance regulator). The protein produced by this gene normally helps salt (sodium chloride) move in and out of cells. In Cystic fibrosis the protein doesn’t work correctly, and so that movement is blocked. This is what causes the abnormally thick sticky mucus to be produced on the outside of the cell. This mucus clogs the airways in the lungs, and increases the risk of infection by bacteria and also blocks ducts in the pancreas, so digestive enzymes can’t get into the intestines.
This faulty gene affects the sweat glands as well. Too much salt is lost through sweat, which can disrupt the delicate balance of minerals in the body.
So a person with CF that does any activity that might cause sweating like being in the hot weather or doing exercise will need to replace the salts they lose- more so than people without CF.
So why do we need salt?
So here’s the science bit…
Every person’s body needs salt to maintain blood pressure and for normal muscle function.
Sodium chloride is an electrolyte, which means it has an electrical charge. When dissolved in fluid, salts tend to break apart into ions, creating an electrically-conductive solution (which means a liquid that electricity can pass through.)
Sodium is responsible for controlling the total amount of water in the body. It is also important for regulating blood volume and maintaining muscle and nerve function. Sodium is mostly found in blood, plasma, and lymph fluid. Sodium is one-half of the electrical pump in your cells (Sodium is pumped out of the cells, and potassium is pumped into the cells, creating an electrical charge that leads to the transmission of impulses along nerves. The sodium-potassium pump is also necessary for muscles to contract.) that keeps electrolytes in balance between the inside (intracellular) and outside (extracellular) of your cells. It is a positively charged ion.
Chloride is the major negatively-charged ion in your body and is primarily found in extracellular fluid (outside of cells). It works closely with sodium to maintain proper balance and pressure of the various fluids of the body (blood, inside cells, and the fluid between cells). It is also vitally important for maintaining proper acidity in the body, passively balancing out the positive ions of blood, tissue and organs.
So what happens if you have too little salt?
Low levels of salt in the body can cause hyponatraemia- this is where the level of water in your cells becomes abnormally high and the cells start to swell. Symptoms of hyponatraemia include:
Loss of energy and fatigue
Restlessness and irritability
Muscle weakness, spasms or cramps
nausea and vomiting
So, that’s why, in a nutshell, people with Cystic Fibrosis need extra salt!
Remember, you should always check with your CF team before taking prescribed salt tablets/solution or adding excessive amounts of salt to your diet.