Table 2: Effects of vitamin D supplementation in insulin resistance.

StudyIntervention SubjectsEffect

Pittas et al. [26]vitamin D (700 IU/d for 3 years) and calcium intake314 Decreased insulin resistance
Inomata et al. [99]
1α(OH) vitamin D
(400 IU/d for 3 wks)
14 noninsulin-dependent diabetes(1) Increased insulin secretion
(2) A reduction in serum free fatty acid levels
Gedik and Akalin [100]1,25 (OH)2 vitamin D
(2000 IU/d for 6 months)
4 patients with vitamin D deficiencyIncreased insulin secretion
Borissova et al. [101]1,25 (OH)2 vitamin D
(1332 IU/d for 1 month)
10 females with type 2 diabetesA decrease of 21.4% in insulin resistance
Orwoll et al. [102]1,25 (OH)2 vitamin D
(200 IU/d for 4 d)
20 patient with type 2 diabetesNo effect on insulin, glucose, c-peptide
Taylor and Wise [103]1,25 (OH)2 vitamin D
(300000 IU intramuscular)
3 Asians with type 2 diabetesIncreased insulin resistance
Ljunghall et al. [104]1α(OH) vitamin D
(30 IU/d for 3 months)
65 Caucasian men with impaired glucose toleranceNo difference in insulin resistance
Kumar et al. [105]1,25 (OH)2 vitamin D
( 2000 IU/d for 1 month)
1 vitamin D deficient hypocalcemic womanIncreased glucose tolerance and β-cell function