Vitamins fall into two classes: fat-soluble and water-soluble. Their solubility will determine how the vitamin is absorbed and transported by the bloodstream, whether or not it can be stored in the body, and how easily it can be lost from the body. Requirements for each of the vitamins are based on age, gender, pregnancy, and lactation. You can find them at http://www.iom.edu/Object.File/Master/7/296/
Ultimately, all of these carbohydrates are broken down and converted into glucose. Complex carbohydrates take longer to digest and provide fiber, so they are the best source of carbohydrates. This does not mean that fruit or milk is not a healthy source. The skin and the seeds in the fruit are sources of fiber, so they contain both simple and complex carbohydrates. Milk sugar has been shown to enhance calcium absorption, making it an asset to your health. Again, the quantity consumed is going to be the key.
Those issues can be part of what's known as the “keto flu,” Warren says. Other side effects of the keto diet, all of which are tied to carb withdrawal, can include lightheadedness, nausea, mental fog, cramps, and headaches, in addition to tiredness. Luckily, the keto flu doesn't usually last more than a week—which is coincidentally about when people start to see the number on the scale go down, says Warren.
If you eat fewer calories than you burn, you'll lose weight. But when you're hungry all the time, eating fewer calories can be a challenge. "Studies show people who eat 4-5 meals or snacks per day are better able to control their appetite and weight," says obesity researcher Rebecca Reeves, DrPH, RD. She recommends dividing your daily calories into smaller meals or snacks and enjoying most of them earlier in the day -- dinner should be the last time you eat.