Electrolyte supplements: which ones do anything

The very ordinary causes of week-two malaise: inadequate hydration, low sodium intake, too-rapid calorie deficit, and inadequate sleep are more common causes of fatigue and malaise than compound toxicity.

post #15 answers the question as asked. The question underneath it is different.

Magnesium: deficiency during weight loss is common and symptoms (fatigue, muscle cramps) are nonspecific. Supplementation is inexpensive and low-risk if needed.

Coming back to post #15, because the follow-up matters more than the original answer.

Water intoxication: drinking excessive water (more than a few liters per day for extended time) without electrolyte replacement can cause hyponatremia. This is rare but serious. Balance fluid with electrolytes.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

Worth separating two things that post #15 runs together.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

post #19 is right about the mechanism and I think understates the practical bit.

Fluid intake: baseline needs increase with gastrointestinal effects and exercise. Thirst is not a reliable guide during appetite suppression. Drinking regularly (not just when thirsty) is prudent.

Exercise and electrolyte losses: sweating during exercise increases sodium and potassium losses. Electrolyte replacement during or after intense exercise helps maintain balance.

Orthostatic symptoms: dizziness on standing after lying down can indicate dehydration or electrolyte depletion. Increasing fluids, salt, and potassium usually resolves it.

Picking up post #20: that is the part I would want checked first.

Sodium: losing weight involves losing some sodium. Electrolyte drinks or salty foods help maintain sodium balance. Very low sodium intake on these compounds raises orthostatic symptoms risk.

Potassium: similar to sodium; losing weight involves some potassium loss. Bananas, sweet potatoes, and other potassium-rich foods help. Severe depletion is rare but symptomatic (weakness, palpitations).

Lab testing: if symptoms are severe or persistent, checking electrolytes and minerals (sodium, potassium, magnesium, calcium) and interpreting them in context of losses during weight loss is reasonable.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

This follows post #24 rather than contradicting it.

Magnesium: deficiency during weight loss is common and symptoms (fatigue, muscle cramps) are nonspecific. Supplementation is inexpensive and low-risk if needed.

I read post #26 twice before replying, because I had assumed the opposite.

The very ordinary causes of week-two malaise: inadequate hydration, low sodium intake, too-rapid calorie deficit, and inadequate sleep are more common causes of fatigue and malaise than compound toxicity.

post #28 answers the question as asked. The question underneath it is different.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

On post #26 — agreed on the reasoning, with one qualification.

Water intoxication: drinking excessive water (more than a few liters per day for extended time) without electrolyte replacement can cause hyponatremia. This is rare but serious. Balance fluid with electrolytes.