Replies

Lower prediagnostic serum 25-hydroxyvitamin D concentration is associated with higher risk of insulin-requiring diabetes: a nested case–control study(PDF)

Abstract
Aims/hypothesis Low serum 25-hydroxyvitamin D [25 (OH)D] concentration may increase risk of insulin requiring diabetes.
Methods A nested case–control study was performed using serum collected during 2002–2008 from military service members. One thousand subjects subsequently developed insulin-requiring diabetes. A healthy control was individually matched to each case on blood-draw date (±2 days), age (±3 months), length of service (±30 days) and sex. The median elapsed time between serum collection and first diagnosis of diabetes was 1 year (range 1 month to 10 years). Statistical analysis used matched pairs and conditional logistic regression.
Results ORs(odds ratios) for insulin-requiring diabetes by quintile of serum 25(OH)D, from lowest to highest, were 3.5 (95% CI 2.0, 6.0), 2.5 (1.5, 4.2), 0.8 (0.4, 1.4), 1.1 (0.6, 2.8) and 1.0 (reference) (p_trend <0.001). The quintiles (based on fifths using serum 25(OH)D concentration in the controls) of serum 25(OH)D in nmol/l, were <43 (median 28), 43–59 (median 52), 60–77 (median 70), 78–99 (median 88) and ≥100 (median 128).
Conclusions/interpretation Individuals with lower serum 25(OH)D concentrations had higher risk of insulinrequiring diabetes than those with higher concentrations. A 3.5-fold lower risk was associated with a serum 25 (OH)D concentration ≥60 nmol/l.

P.S. The press release described the serum concentration of 25-hydroxyvitamin D in terms of ng/ml, i.e. nanograms per milliliter. The original citation expressed it in terms of nmol/l, i.e. nanomoles per liter. The latter is most likely the European convention.

P.P.S. I interpret p_trend <0.001 as the chance of getting these results as just by chance as less than 1 in a 1000 with the same sampling method. Most results are considered statistically significant when you would expect those results by chance less than or equal to 1 out of 20.

Diabetes and immunology lists, together again.

Maybe I can get my doctor to prescribe 2 weeks in the sun at a nice beach resort?

I have been taking 5000iu of Vitamin D3-5 daily for five years.

I know it’s just anecdotal, but I have not been sick during that time.

It’s cheap. Buy it at Wally.