welcome to healthcaremagic
You stated that you had taken sun cap and your weight reduce but i dont think there is some corelation with your weight loss
with this cap. Do you had anyother related symptoms along with this? IF your weight loss is sudden then it may be due many reasons. IF gradual loss of weight and any other symptoms if you had you had to rule out some other examination for confirmation.
If you continue to loss the weight please consult with your nearest Physician