Electrolyte Hydration RTD

Many people reaching for electrolytes don't actually need them, and those who do often need a different product from the one they picked up. These are the questions our naturopaths ask in store.

A good fit if

• You're losing fluid through vomiting, diarrhoea or heavy sweating
• You're training long or hard in the heat and plain water isn't enough
• You want an oral rehydration sachet for the medicine cabinet
• You've been advised to change your balance of sodium to potassium

Check with us first if

• You have kidney disease, because your body handles potassium differently and potassium taken by mouth can build up.
• You take heart or blood pressure medicine, especially an ACE inhibitor.
• You're buying for a young child or an older person who's unwell.
• You already take a potassium or magnesium supplement.
• You're using electrolytes for cramps, where the evidence is genuinely mixed.

• Oral rehydration salts (ORS). Best known for: Illness: vomiting, diarrhoea, and getting a child rehydrated. Absorption: Made to a WHO and UNICEF formula for sodium, potassium, glucose and concentration (osmolarity). Typical use: The only electrolyte format whose make-up is set in Australian law.
• Sports hydration powders. Best known for: Training and sweating in hot weather. Absorption: What is in them varies hugely by brand, and they are often built around flavour. Typical use: Check the sodium figure. It is the one doing the work.
• Effervescent tablets. Best known for: Convenience, and a measured dose in every tablet. Absorption: Dissolved before you drink it, so there is no powder to scoop. Typical use: Watch the potassium per tablet if you take heart or blood pressure medicine.
• Ready-to-drink bottles. Best known for: No mixing. Absorption: The same salts, with more packaging and usually more sugar. Typical use: Convenient rather than different.
• Plain sodium chloride (item 4581). Best known for: Table salt, allowed in listed medicines with no conditions at all. Absorption: The simplest sodium source there is. Typical use: Worth remembering before you reach for a branded blend.

Reference values. The NHMRC sets recommended intakes for sodium, potassium, magnesium and calcium one by one, rather than for electrolytes as a group. Ordinary food and drink covers them for most people, most of the time.

Typical supplemental range. Oral rehydration sachets are made to a set formula, with sodium, potassium, glucose and total concentration matching the WHO and UNICEF criteria once mixed. Sports powders vary much more, and sodium is the figure worth comparing. Australian law caps potassium chloride at 550 mg per dose unit in anything that isn't an oral rehydration product.

Upper level. No single upper limit applies to a blend. The firm numbers are for each ingredient: 550 mg of potassium chloride per dose unit outside oral rehydration products, and a 3.75% concentration limit for dental use.

Worth knowing. When you're unwell, the formula matters, and a rehydration sachet is the product made for it. For sweating, sodium is the number to compare. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Table salt: the simplest sodium and chloride source
• Fruit and vegetables: the main dietary potassium sources
• Dairy, nuts and leafy greens: contribute calcium and magnesium

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• You have kidney disease. Oral potassium chloride must carry an Australian warning about this. In chronic kidney disease the usual potassium-driven loss of sodium in urine does not happen, and potassium taken by mouth builds up.
• You take heart or blood pressure medicines. Oral potassium chloride must carry an Australian warning about this, and ACE inhibitors change how your body handles potassium.
• You are being treated for high blood pressure. A rise in blood pressure has been seen at high potassium intakes in people on blood pressure medicines.
• Children. The required warning includes "Keep out of reach of children", and a dehydrated child needs a medical check.
• Blends containing sodium sulfate. It must carry a laxative warning when it is not meant as a laxative.
• You want electrolytes for cramps. The evidence is inconsistent, and magnesium in particular was found unlikely to help older adults.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.