Recommended Vaccines: Yellow fever vaccination is recommended for travelers to Colombia, but if you will not be traveling beyond the cities of Bogotá, Cali, or Medellín, you are at lower risk and may consider skipping it. Routine vaccines should be up to date, and hepatitis A and typhoid vaccines should be administered as well. If you are traveling to southern Colombia, hepatitis B is advisable.
Malaria: Risk in all rural areas at altitudes below 2,624 feet (800 m). No risk in Bogotá and vicinity. If you are traveling to a risk area, your doctor will recommend either atovaquone/proguanil, doxycycline, or mefloquine as an antimalarial. Chlorquine is not effective in this region and shouldn't be used.
Other Issues: Other mosquito-borne illnesses such as dengue and jungle yellow fever crop up in Colombia, according to the Pan American Health Organization. Bring your DEET, your long sleeves, and closed shoes (not sandals), even for city wear. (Usually at BabyZone we like to advocate "green" approaches, but in some cases the long-term risk of contracting an insect-borne disease trumps the anxiety over using a 10-syllable chemical like N-diethylmetatoluamine, aka DEET. If you are trying to induce lactation, however, use as little DEET as you can.)