Supplementation with High Doses of Vitamin D to Subjects without Vitamin D Deficiency May Have Negative Effects: Pooled Data from Four Intervention Trials in Tromsø. (14th March 2013)

• Record Type: Journal Article
• Authors: Jorde, Rolf; Strand Hutchinson, Moira; Kjærgaard, Marie; Sneve, Monica; Grimnes, Guri
• Other Names: Bizzarri C. Academic Editor.; Giampietro O. Academic Editor.; Saxe A. Academic Editor.; Schiettecatte J. Academic Editor.
• Is Part Of: ISRN endocrinology. Volume 2013(2013)
• Publication Date: 2013-03-14
• Subjects: Endocrinology -- Periodicals; Endocrine System Diseases; Endocrinology; Endocrinology; Electronic journals; Periodical; Fulltext; Internet Resources; Periodicals; Periodicals; 616.4
• DOI: 10.1155/2013/348705
• Languages: English
• ISSNs: 2090-4630

Abstract

Abstract : Data were pooled from four randomized clinical trials with vitamin D performed in Tromsø with weight reduction, insulin sensitivity, bone density, and depression scores as endpoints. Serum lipids, glycated hemoglobin (HbA 1c ), and high sensitivity C-Reactive Protein, (HS-CRP) were measured at baseline and after 6–12 months of supplementation with vitamin D 20 000 IU–40 000 IU per week versus placebo. A total of 928 subjects who completed the interventions were included. At baseline the mean serum 25-hydroxyvitamin D (25(OH)D) level in those given vitamin D was 55.9 (20.9) nmol/L and the mean increase was 82.4 (40.1) nmol/L. Compared with the placebo group there was in the vitamin D group at the end of the studies a slight, but significant, increase in HbA 1c of 0.04%, an increase in HS-CRP of 0.07 mg/L in those with serum 25(OH)D < 50 nmol/L, and in those with low baseline HDL-C and serum 25(OH)D < 50 nmol/L a slight decrease serum HDL-C of 0.08 mmol/L (P < 0.05 ). No serious side-effects were seen. In conclusion, in subjects without vitamin D deficiency, there is no improvement in serum lipids, HbA 1c, or HS-CRP with high dose vitamin D supplementation. If anything, the effect is negative.