I'm a 16 year old girl and I'm 5'8 and want to gettaller. Can anyone recommend me diet/ exercise/ vitamins/ pills?

Depends. Most women finish growing taller at 16-17 or within 3 years of first menses. The hormones that trigger puberty start a growth spurt but eventually the growth centers will close. Once the growth centers close you are done.A single x-ray of your wrist/hand could be examined for growth centers.If open you could grow taller,if closed you are done.No special exercise,diet/vitamin or pills add height.
Unless you plan... To take dangerous and illegal drugs, you will just grow to whatever height your specific genetics will dictate. You have maybe a year yet before the final growth plates close and you will stop growing taller.
Once you complete. Puberty (which may have occurred) you will not grow taller. However exercise ; healthy eating is very important.