Dry skin can be due to low essential fatty acids. How is your hair? Mine used to be quite dry and split easily until I started taking Fish Oils and flax seed oil and increased what I ate in the way of healthy fats. They dont actually make you fat, but do help to increase metabolism, and regulate appitite. My skin is much better now too.

There is some info on electrolytes below, from an article which might be worth a look.

From http://www.mothernature.com/Library/Bookshelf/Books/10/55.cfm

Balancing Electrolytes

It is well-documented that one of the consequences of eating disorders is a potentially life-threatening electrolyte imbalance. Electrolytes are minerals that, when dissolved in the body’s fluid, become electrically charged. They are responsible for controlling heart rate and blood pressure.

Potassium and sodium are the body’s major electrolytes. Although potassium deficiency is not common, rapid weight loss and dehydration can cause potassium to plummet, leaving you at risk for serious heart problems, including heart attack.

“People with eating disorders need to have these nutrients stabilized as quickly as possible,” says Dr. Beasley, who often recommends supplements of potassium as well as magnesium, another electrolyte that can lead to serious heart problems if deficient. “I have never seen an eating disorder patient who didn’t have major deficits of these nutrients.”

Because too much potassium can make you ill, it is best to get the Daily Value of this mineral (3,500 milligrams) by eating fruits and vegetables such as bananas, oranges, spinach and celery. You can get 885 milligrams just by eating half of a cantaloupe. Magnesium supplements are available in various forms, but eating seafood and green, leafy vegetables can help you easily get your Daily Value of 400 milligrams. People who have heart or kidney problems or diabetes should check with their doctors before supplementing these minerals.

Experts recommend that people with eating disorders have a physician monitor all of their electrolytes: potassium, magnesium and sodium as well as phosphorus and chloride, which can also become dangerously low.

Calcium to Protect Bones

Calcium, an essential mineral in the development and maintenance of bone health, is one of the nutrients most likely to be deficient in people with eating disorders. Those who treat eating disorders say the impact of severe calcium deficiency, especially when combined with amenorrhea, can be devastating.

“We see 28-year-old women with the bones of 80-year-olds,” says Tuttle. “They are already in the middle stages of osteoporosis. It’s sad, but fortunately, sometimes this serious medical issue is the alarm that helps a woman choose to move forward in her recovery.” Tuttle notes that doctors often give women with eating disorders calcium supplements of 1,000 milligrams (the Daily Value) or more while also attending to the amenorrhea.

“Certainly, it’s important that these girls get sufficient amounts of calcium in their diets,” says Steven A. Abrams, M.D., a research scientist at the U.S. Department of Agriculture Children’s Nutrition Research Center and associate professor of pediatrics, both at Baylor College of Medicine in Houston. “But supplements may not be sufficient to resolve osteoporosis if hormonal inadequacy remains present.”

Drinking skim milk is a good way to increase your dietary calcium, as just three cups packs more than 1,000 milligrams. Other sources include broccoli, tofu and fortified orange juice.

Prescriptions for Healing

Although eating food is absolutely essential to preventing the damage that eating disorders can do to the body, some doctors believe that vitamin and mineral supplements can expedite the process of recovery and healing.

Nutrient Daily Amount

Calcium 1,000 milligrams

Iron 18 milligrams

Magnesium 400 milligrams

Niacin 20 milligrams

Potassium 3,500 milligrams

thiamin 1.5 milligrams

Vitamin A 5,000 international units

Vitamin E 30 international units

Zinc 15 milligrams

Plus a multivitamin/mineral supplement containing the Daily Values of all essential vitamins and minerals

MEDICAL ALERT: Experts warn that supplements cannot take the place of food in someone who has an eating disorder. The body will not properly absorb and use vitamins and minerals without also receiving adequate calories. It is important to be under a doctor's care when treating this condition.

People who have heart or kidney problems should check with their doctors before taking magnesium supplements.

People who have kidney problems or diabetes should check with their doctors before taking potassium supplements.

If you are taking anticoagulant drugs, you should not take vitamin E supplements.