FOR THE TREATMENT OF SIMPLE NUTRITIONAL DEFICIENCIES COLECALCIFEROL OR ERGOCALCIFEROL ARE GENERALLY PREFERRED. THEY ARE USUALLY GIVEN BY MOUTH, BUT MAY ALSO BE GIVEN BY INTRAMUSCULAR INJECTION. A DOSE OF 10 MICROGRAMS (400 UNITS) DAILY IS GENERALLY SUFFICIENT IN ADULTS FOR THE PREVENTION OF SIMPLE DEFICIENCY STATES; IN THE UK, 20 MICROGRAMS (800 UNITS) DAILY IS RECOMMENDED IN SOME ETHNIC GROUPS CONSUMING UNLEAVENED BREAD, AND IN THE ELDERLY LIVING ALONE. DEFICIENCY DUE TO MALABSORPTION STATES OR LIVER DISEASE OFTEN REQUIRES HIGHER DOSES FOR TREATMENT, OF UP TO 1 MG (40 000 UNITS) DAILY. DOSES OF UP TO 2.5 MG (100 000 UNITS) DAILY MAY BE USED IN THE TREATMENT OF HYPOCALCAEMIA DUE TO HYPOPARATHYROIDISM. BY MOUTH OR BY IV INJ OVER 30 SEC, ADULT & CHILD OVER 20 KG, INITIALLY 1 MCGS DAILY (ELDERLY 500 NANOGRAMS), ADJUSTED TO AVOID HYPERCALCAEMIA; MAINTENANCE, USUALLY 0.25-1 MCG DAILY; NEONATE AND PRETERM NEONATE INITIALLY 50-100 NANOGRAMS/KG DAILY, CHILD UNDER 20 KG INITIALLY 50 NANOGRAMS/KG DAILY .PARICALCITOL IS GIVEN INTRAVENOUSLY IN THE USA AT A DOSE OF 40 TO 100 NANOGRAMS/KG ON ALTERNATE DAYS OR LESS FREQUENTLY; IN THE UK THE INITIAL DOSE (IN MICROGRAMS) IS CALCULATED BY DIVIDING THE BASELINE INTACT PARATHYROID HORMONE CONCENTRATION (IN PICOGRAMS/ML) BY 80. THE DOSE MAY BE INCREASED OR DECREASED IF NECESSARY BY 2 TO 4 MICROGRAMS AT INTERVALS OF 2 TO 4 WEEKS. IT IS ALSO GIVEN BY MOUTH EITHER AS A DAILY DOSE OR THREE TIMES WEEKLY (NO MORE FREQUENTLY THAN EVERY OTHER DAY). AGAIN, THE INITIAL DOSE IS BASED ON BASELINE INTACT PARATHYROID HORMONE CONCENTRATIONS. IF THESE ARE 500 PICOGRAMS/ML OR LESS, PARICALCITOL IS GIVEN AT A DOSE OF 1 MICROGRAM DAILY, OR 2 MICROGRAMS THREE TIMES WEEKLY; IF THEY ARE ABOVE 500 PICOGRAMS/ML, PARICALCITOL 2 MICROGRAMS DAILY, OR 4 MICROGRAMS THREE TIMES WEEKLY IS SUGGESTED. DOSES ARE TITRATED ACCORDING TO PARATHYROID HORMONE CONCENTRATIONS.