24 months of age were measured with a wooden infantometer while lying down, those over 24 months old were measured in a standing position, with the same infantometer.
Hemoglobin and serum retinol: For comparability with baseline and midterm results blood was obtained from the children and mothers. Blood from the mothers and children under the age of six months was taken from the left ring finger with a disposable lancet. If the child was over the age of six months the blood was taken from the cubital vein, with a heparinized syringe for immediate analysis of hemoglobin concentration, and for later analysis of serum retinol levels. The needle used was one inch long and 21 gauge. Once the blood was obtained (through the lancet or syringe) the second or third drop was placed in a Hemocue cuvette. These were inserted within five minutes into the portable hemoglobinometer (Hemocue®). Results for mother and child were written and given to the mother (or other family member). If found anemic (See Table 2.) the mothers were given counseling and one packet of heme iron fortified cocoa that they were to use for twenty days. The venous blood that was obtained from the children>6m was then covered in aluminum and transported to the field laboratory. The field lab consisted of a large black tarp, that when erected created a space that was protected from sunlight (UV rays). Here the blood sample was centrifuged by hand for 5 minutes. Then, approximately 1.0 ml of plasma was transferred into another vial. This vial was coded according to the cluster and household, wrapped in aluminum foil and then deposited in a thermos with ice packets to keep the cold chain intact and the specimen viable. The vials were later transported to Lima (UPCH) for the analysis of serum retinol content.
Table 2. Cut off points for anemia
Sex and age group
Infants (6-12 months old)
Preschool children (1-5 years)
Non-pregnant (15-45 years )