Most of what people are saying are true with regards to the mineral intake. Here's an excerpt from an article I wrote about going onto Keto (From
http://www.facebook.com/KetoLiving ):
General Ketogenic Guidelines
1) Get your carbohydrate intake down. Ketogenic in most people requires you to have <20g, but even reducing carbohydrate intake by any amount is better than none. [Note: If you consume a lot of carbs currently, most people find the transition easier to reduce your carb intake gradually to reduce withdrawal symptoms IE "Keto Flu"]
2) Keep your Protein intake MODERATE. Some people think (maybe as a remnant of their beliefs from previous diets) that Ketogenic means Low-Carb/High-Protein. The majority of your caloric intake has to come from fats (which aren't bad for you!). Coconut oil also has some anecdotal benefits that might help increase your fat intake as well. The macro to aim for (assuming you measure) should be 60 fat/30 protein/10 carbs (with the extreme being cutting carbs to almost 0 - but not counting carbs coming from leafy green vegetables).
3) Hydrate! Especially when you withdraw from carbs, you will expel a LARGE amount of water weight initially (your body is expelling the excess glucose in your system in the absence of insulin). This is the reason why you lose so much weight initially. YOU WILL GAIN THIS WEIGHT BACK!!! People think that this lifestyle doesn't work because they regain the water weight under ketogenic conditions, and they completely plateau for a week, maybe 2. This is completely normal.
4) Supplementation. This is a bit of a gray area, but a lot of evidence shows that people benefit on a muscular level (especially through the transition phase within the first month of cutting carbs) to supplement with extra sodium, potassium, and magnesium. Failure to do so WILL very likely result in lethargy, brain-fog, and mood disorders. You need these electrolytes in your system to keep your muscles and brain functioning normally (especially potassium).