Vitamin D therapy in patients with primary hyperparathyroidism and hypovitaminosis D.
OBJECTIVE
To determine whether vitamin D repletion of patients with primary hyperparathyroidism (PHPT) and vitamin D deficiency or insufficiency (hypovitaminosis D) has deleterious clinical and/or biochemical effects.


METHODS
Prospective audit of the effect of vitamin D repletion on biochemical data in 56 patients with PHPT. Patients were treated with 50,000 units of vitamin D2 weekly for 8 weeks with biochemical measurements at 5 and 10 weeks, and subsequently after 12 weeks on 800 units of vitamin D3 daily, and in those with hypovitaminosis D after 12 weeks of up to 100 000 units of vitamin D(2) monthly.


METHODS
Serum calcium, albumin, phosphorus, 25-OHD, intact parathyroid hormone (PTH) and urine calcium/creatinine (Ca/Cr) ratios were measured before and during vitamin D therapy.


RESULTS
Patients treated with 50,000 units of vitamin D2 weekly for 8 weeks resulted in a significant increase in serum 25-OHD levels from 36.4 to 89.4 nmol/l at 5 weeks (P<0.0001) and 88.6 nmol/l at 10 weeks (P<0.0001). There were no significant changes in serum calcium. At 10 weeks, there was a non-significant decrease in serum PTH and in urine Ca/Cr ratios. None of the patients developed any calcium-related adverse events. Subsequently, patients with subnormal 25-OHD levels on 800 units of vitamin D daily were treated for the next 12 weeks with up to 100,000 units of vitamin D2 monthly with normalization of serum 25-OHD in all but 4 patients.


CONCLUSIONS
These data fail to demonstrate any adverse effects of vitamin D repletion in PHPT.
Tucci
J R
JR
Division of Endocrinology, Department of Medicine, Roger Williams Medical Center, 825 Chalkstone Avenue, Providence, Rhode Island 02908-4728, USA. umgtucci@yahoo.com
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood / Q000652:urine; D003401:Creatine / Q000652:urine; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D014807:Vitamin D / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy*; D014815:Vitamins / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood
D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; D010758:Phosphorus; D003401:Creatine; D002118:Calcium