Raltegravir with Calcium CarbonateThe Influence of Concurrent Oral Calcium Carbonate Supplementation on Steady State Pharmacokinetics of Oral Raltegravir.

Inclusion Criteria:

1. Patient must be a healthy HIV infected male or female.
2. Patient must be between the ages of 18 and 65.
3. Patient must be undergoing stable effective ART and must be compatible with once a-day study raltegravir or be separable from study calcium co-administration by at least 8 hours in a twice-a-day dosing schedule.
4. Patient must have a viral load < 50 copies/mL within 3 months of study Day 1.
5. Patient must be medically stable at time of study, with no evidence of acute illness as per physician assessment.
6. Patient must be able to read, understand and sign a written informed consent prior to initiation of the study.
7. Patients must be willing to stop using any herbal or natural health products for 2 weeks prior to Day 1 and during the study.

Exclusion Criteria:

1. Patient on any medications that can alter the drug absorption of study medications other than oral contraception and stable effective ART. This includes no micronutrient mineral and trace element supplementation (except calcium).
2. Patient donated blood with the 30 days prior to study start.
3. Persons with prior gastric or enteric surgery, acute medical illness, or anticipated use of other medications, supplements or treatments.
4. Patient has a BMI > 30
5. Patient is unable to understand, consent and adhere to study protocol and procedures.
6. Women who are pregnant, breast-feeding, and not willing to practice contraception during the study period plus one month.