My creatinine serum is 0.50 and i am 37 yrs old female. is it ok ?

Normal range: Yes, the creatinine is in the normal range for someone your age. However, creatinine isn't the best measure for kidney function. If you are concerned, you can calculate a glomerular filtration rate (GFR) which is a better measure of renal impairment. The GFR in a young healthy person should be > 90ml/min, but GFR calculators account for gender, race, age and weight to give a more accurate measure.