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Test Code LACTO Lactose Tolerance, Serum

Additional Codes

Ordering Mnemonic




Performing Laboratory

Holland Hospital Laboratory Services

Specimen Requirements

Patient Preparation
Draw specimen following an overnight (12-14 hour) fast. Be certain that patient is not receiving intravenous glucose (dextrose) solutions during testing period. Test cannot be properly interpreted if patient vomits or has diarrhea during testing, although diarrhea or abdominal distress in response to ingested lactose may be evidence of intolerance.


Specimen Collection

Container/Tube: Mint-top (lithium heparin) tube for each timed specimen

Specimen Volume: 1 mL of plasma

Collection Instructions: Fasting

Note: 1. After fasting specimen is drawn, patient is given a preparation of 50 g of lactose in 200 mL of cool water.

2. Draw blood specimens at 30-, 60-, and 120-minutes after ingestion of lactose.

3. Indicate draw times.

4. Label specimens appropriately (corresponding draw time).

Specimen Transport Temperature


Day(s) Test Set Up

Monday through Friday

Test Classification and CPT Coding

82951 x 3-lactose
82952-Each additional specimen

Reference Values

Normal lactose activity: rise of 25 mg/dL in blood glucose
Deficient lactose activity: rise of <20 mg/dL in blood glucose