Yes, it's common. LCHF diets cause your body to dump sodium. You need a potassium AND magnesium supplement.

Could also be magnesium. I take two of these every night: http://www.amazon.com/Solgar-Magnesium-Citrate-Tablets-Count/dp/B0002SKUWI

Apparently Magnesium Oxide, which is the form that you'll find it in if you look at all of the types available in most CVS stores or WalGreens or whatever, is not absorbed very well and is not recommended for ketoers. Magnesium Citrate or Chelated Magnesium is. Magnesium is pretty easy to figure out. Calf Cramps are super easy to get if its low, and if its too high you'll likely end up with diarrhea. So you can start by taking 1 and seeing if it fixes the cramps over a few days, if it doesn't, go up to 2.

For Potassium I switched to "Lite Salt" awhile back which is half sodium/half potassium. The common foods with a lot of potassium recommended when this topic comes up (avocado! and liver I believe) I don't really like outside of very small servings for a bit of flavor. There is some potassium in most meats too, and in broccoli and spinach, I tend to eat some spinach every day but still feel like I need to supplement up a bit with Lite Salt.

Probably not. Multis usually have nominal amounts of those types of things. Try the supplements if you're not getting enough through diet. Be careful if you get Mag Citrate. It's commonly used as a laxative.

I supplement potassium citrate and magnesium citrate while eating keto. I tend to eat enough sodium so I don't feel the need to eat extra lite salt. I get bad leg cramps if I forget my supplements a couple days in a row. The FDA regulated potassium pills so you'll only find them in 99mg capsules which is like 3% of your daily requirement. I make my own OO capsules with potassium citrate powder on Amazon and each one works out to be 265mg. I will take 3-6 of these a day depending on what other potassium rich foods I'm eating. I also take 400mg of magnesium citrate each day which are just two 200mg tablets. Here are the products I've purchased for potassium.
http://www.amazon.com/The-Capsule-Machine-00-Kit/dp/B006OQ4316/ref=sr_1_1?ie=UTF8&qid=1408162550&sr=8-1&keywords=00+capsule+machine
http://www.amazon.com/bulk-wholesale-Empty-Gelatin-Capsules/dp/B00428B6X6/ref=sr_1_1?ie=UTF8&qid=1408162543&sr=8-1&keywords=00+capsules
http://www.amazon.com/BulkSupplements-Potassium-Citrate-Powder-grams/dp/B00ENSA942/ref=sr_1_1?ie=UTF8&qid=undefined&sr=8-1&keywords=potassium+citrate+powder

I have had some issues in the past. I agree that magnesium through food or supplement can help. It is difficult to get 400 mg of magnesium through food. Eating magnesium rich foods like kale or a banana only adds 30-50 mg at a clip. Supplementation when you have a problem may be the answer. It is difficult to find a supplemental form that is bioavailable. Magnesium oxide, found in many supplements, is not very bioavailable. You may have to do an internet search for the best bioavailable form.

I have tried to keep a good ratio of potassium to sodium like something above 3:1. It is a challenge if you eat processed foods.

I also stay away from foods later in the day that have a diuretic effect and drink 8 ounces of water before retiring.

Don't know if this is a solution but I have not had a problem in 6 months or so. Good luck.

Directly quoted from Volek and Phinney , The Art and Science of Low Carb Living, pages 243-244:

"9. Muscle Cramps: Unnatural Complications of a Highly Refined Diet"

A distressing number of otherwise healthy people have frequent muscle cramps, and in the worst case, a muscle cramp of the heart equals sudden death. Physicians don't lie to deal with muscle cramps because the only effective medication we had to stop them was banned in 1992 due to unacceptable side effects.

Muscle cramps are the end result of many contributing factors, including overuse, dehydration, and mineral inadequacies. Low serum potassium is not uncommon in people with frequent cramps, so physicians often try potassium supplements. However there is a daisy-chain leading back from muscle cramps to low blood potassium to intracellular magnesium depletion. Low carbohydrate diets don't cause muscle cramps per se (meat and leafy greens are good sources of magnesium), but neither do they miraculously get better on low carb regimens unless the underlying problem is dealt with. This is just one more reason why leafy greens and home-made broths (good sources of magnesium
0 are desirable components of a healthy low carb diet.

So here's the shortcut to ending most nocturnal or post-exercise muscle cramps. Take 3 slow-release magnesium tablets daily for 20 days. The proprietary brand-name product is 'Slow-Mag', but there are a number of equally effective generics at a fraction of the brand-name price (e.g.Mag-64 or Mag-Delay). Most people's cramps cease within 2 weeks of starting 'Slow-Mag', but you should continue to take the full 20-day course (60 tabs per bottle at 3 per day lasts 20 days). If the cramps return, do it again, and then continue taking one tab per day. If the cramps return, take 2 tabs per day. Most people can be titrated to remain cramp-free by this method. Why use a more expensive slow-release magnesium preparation like Slow-Mag? Because magnesium oxide preparations like 'milk of magnesia' cause diarrhea, passing through the small bowel before they can be effectively absorbed.

WARNING: The only contraindication to oral magnesium supplements is severe renal failure (e.g., a GFR <30). If you have any history of kidney problems or known loss of kidney function check with your doctor before taking Slo-Mag or its generic equivalents. "

I also eat either Kale or spinage every day. I make my own bone broth from chicken bones, I use the low salt with 50% sodium,50% potasium- i put that on all my food and add it to bone broth. I am still waiting for my high dose magnesium supplements to arrive and praying they increase my energy. I have not had any cramps.

Yes, I have too. V-8 Juice - low sodium has over 900 mg of Potassium, no added sugar, and it a good dose of vegetables in a glass! It is my go-to source for quickly digestable potassium.

Brilliant!! IDK why I didn't think of this! I've been doing Avocados. The leg cramps are my worse side effect.

I know this is an old thread, but thought some may reference it.....

I never had keto flu, although I had a couple leg cramps, but they were on days I'd zoned a supplement. 　

---

A couple weeks ago, I went to water zumba and came home and nearly passed out in my kitchen. When I analyzed, I realized that I'd forgotten my morning sodium supplement. I drank it and was immediately better.

---

Two years ago, my sister was visiting during the Arizona summer and literally passed out in my kitchen. I had to grab her and slide her to the ground so she didn't whomp her head on the counter or tile floor. I ended up slapping her and pouring water over her, then giving her salt water to drink. Her electrolytes were beyond depleted. You just simply do not ignore them. That's what prompted me to be on point with my electrolytes from the start.

---

I choose to use sole water (1 tbsp twice a day in 20 oz of water with citrus essential oils and liquid stevia....it's like Gatorade). I didn't want the carbs in the bouillon. Because I live in the oven called Arizona, and I have upped it to 3 tablespoons a day. I track my sodium intake using MyFitnessPal to ensure that I'm getting a minimum of 5000 mg a day

I also use Jigsaw Magnesium SRT in the morning & Natural Calm right before bed. Watch the generic version of Natural Calm that you may see. The generic that Vitamin Shoppe carries has sugar in it. You can buy Natural Calm at virtually any health food store that you have locally.

In terms of potassium, I eat avocado, spinach, mushrooms quite often. I also use the salt alternative, No Salt, when I am cooking. That also helps with potassium.

Here's a link to the sole recipe/information. http://wellnessmama.com/12158/make-sole/