Keto Electrolytes Made Simple: Sodium, Potassium, Magnesium and Calcium

2017-08-25

In this video

"Electrolytes" gets thrown around in every keto group. My point in this video was that once you name them, you can see where to get them.

[0:00] The four that matter here are sodium, potassium, magnesium and calcium. Naming them makes them easier to find.
[0:30] Sodium is table salt. Potassium is the keto problem, because its usual sources, white and sweet potatoes, are high in carbs.
[1:00] Calcium and magnesium come from leafy greens like baby spinach. Pickle juice has all four.
[1:30] Be careful with potassium and magnesium supplements. They can affect your kidneys and then your heart, and sodium and potassium work as a ratio.
[2:00] Signs I listed: headaches, cramping, irritability, low energy. Bring your doctor in before you supplement.
[2:30] A daily multivitamin covers some of it. Light salt, part potassium chloride, adds potassium.
[3:00] Sports drinks and electrolyte waters hold less than people think. Something like Pedialyte can help acutely with cramps.
[4:00] You can talk yourself into keto flu by avoiding greens, "looking at lettuce like it's the devil" (from the video).
[4:30] Every trip to the bathroom passes salts, so over-hydrating raises your need.
[5:00] Peeing clear means slow down on the water. Pale yellow with symptoms means check your greens and your salt.
[6:00] Swollen hands or feet after pink salt on everything means too much salt.
[6:30] Many people with pre-diabetes or type 2 have some kidney impairment, so electrolytes are a conversation to have with your doctor.

The claim worth unpacking: light salt

My potassium answer was light salt, a mix of sodium chloride and potassium chloride (video lbRPlGZ3Rvw). That's the one piece of this video with a large trial behind it now.

In SSaSS, 20,995 people in rural China were given a potassium-enriched salt substitute. They had fewer strokes, fewer major cardiovascular events and fewer deaths, with no significant difference in serious hyperkalaemia (Neal et al., 2021). The WHO now suggests potassium-containing lower-sodium salt substitutes in place of regular salt, except for people at risk of hyperkalaemia (WHO sodium reduction fact sheet).

That exception is the warning I was trying to give in 2017. If you have kidney disease or heart trouble, or take blood pressure medication, ask your doctor before switching salts or taking potassium pills. This isn't a general disclaimer. It's the specific group the salt-substitute advice leaves out.

For scale, the reference intakes for potassium are 2,600 mg a day for women and 3,400 mg for men (NASEM, 2019). For magnesium, the 350 mg a day upper limit covers supplemental magnesium only, not food (IOM, 1997). That's why greens first, pills second still makes sense.

Then vs now: how much salt

In this video I was cautious about salt. Too much shows up as swelling, and "salt your food properly" was as far as I went (video lbRPlGZ3Rvw).

In a January 2018 broadcast I went much further. I cited a sodium figure near 5,000 mg a day from a mortality study, and I laid out bouillon three times a day with a quarter teaspoon of potassium salt per cup (video -dHjt_Bpruk). The 2018 beginners' video was back to light salt plus broth once or twice a day (video UygKGoP_BtA).

The best-known study matching that description is PURE: 101,945 people in 17 countries, where 3–6 g of sodium a day was associated with fewer deaths and cardiovascular events than intakes above or below that (O'Donnell et al., 2014). It estimated sodium from a single morning urine sample, and it's observational.

The guideline bodies land lower. WHO says adults should stay under 2,000 mg a day (WHO, 2012). The National Academies set an adequate intake of 1,500 mg and say to reduce intake if it's above 2,300 mg (NASEM, 2019). Cutting sodium lowered systolic pressure by about 1 mmHg in white people with normal blood pressure and about 5.5 mmHg in those with hypertension (Graudal et al., 2017).

So my position moved, and the literature is still arguing. If you have high blood pressure, your sodium number is one to set with your doctor. The full debate is in the PURE study explained.

The line that holds up, and the one to check

Holds up: "Name them and they get easier." Keto flu advice gets a lot less mystical when you ask which of the four you're short on and where it comes from.

Holds up: clear urine means ease off the water (video lbRPlGZ3Rvw). More on that in hydration.

Worth checking: the multivitamin as a backstop. The US Preventive Services Task Force calls the evidence on multivitamins insufficient to weigh benefits against harms for preventing heart disease and cancer (USPSTF, 2022). Shortfalls on low-carb diets are real, though. In the A TO Z trial, women on Atkins shifted toward inadequate magnesium, thiamine, folate, vitamin C and iron by eight weeks (Gardner et al., 2010). Food first is still the answer. See do multivitamins work?.

Key points

Four electrolytes: sodium (salt), potassium (hard on keto), magnesium and calcium (leafy greens).
Light salt is a simple potassium source, backed by a large salt-substitute trial (Neal 2021).
Kidney disease, or blood pressure and heart medicines: check with your doctor before switching salts or taking potassium or magnesium pills.
Sports drinks carry less than you'd need. They're for acute cramps, not daily intake.
Clear urine means you're overdoing water. Swelling means you're overdoing salt.
My sodium advice moved between 2017 and 2018, and the studies still disagree on the right number.