My daughter is iron deficient and so takes 25 mg iron daily. If she tries to take it every other day, or even 5 out of 7 days, her iron and hemoglobin start dropping.
Are you sure it's the iron...sounds like you started a lot of new stuff at once. The following info mentions that it could be an electrolyte imbalance.
"It is not known exactly why muscle cramps develop. Insufficient stretching before exercise, exercising in the heat, and muscle fatigue may all play a role in their causation. Imbalances in the levels of electrolytes (sodium, potassium, chloride, calcium and phosphate) in the blood can also lead to muscle cramps."