Vitamin D supplementation boosts insulin sensitivity

Patients given vitamin D showed increased insulin sensitivity over six months, compared with placebo, leading researchers to call for larger, longer term randomised controlled trials.

Vitamin D supplement

Vitamin D supplementation increases peripheral insulin sensitivity in people newly diagnosed with or at high risk of type 2 diabetes mellitus, study results published in the European Journal of Endocrinology have shown (1 July 2019)[1]

The trial included 96 people with high risk of diabetes, or who had early diabetes but were not taking diabetes medication, who were randomly assigned to receive either 5,000 IU of vitamin D3 daily or placebo for six months. Peripheral insulin sensitivity was measured at baseline and six months using a two-hour hyperinsulinaemic-euglycemic clamp and expressed as an M-value.

The results showed that, while the M-value remained constant in the control group during this time, it increased by a mean of 23% in the intervention group, indicating increased insulin sensitivity (mean change: –0.03 vs. +0.92, respectively).

Low vitamin D status is associated with an increased risk of developing diabetes, the researchers explained. However, randomised controlled trials (RCTs) of vitamin D as an intervention to improve insulin sensitivity have provided inconsistent results.

“Larger and longer term RCTs are required to evaluate whether subgroups of patients, including those with low vitamin D status, may benefit from vitamin D supplementation,” the paper concluded.


[1] Lemieux P, Weisnagel S, Caron A et al. Eur J Endocrinol 2019;181(3):287–299. doi: 10.1530/EJE-19-0156

Last updated
The Pharmaceutical Journal, PJ, October 2019, Vol 303, No 7930;303(7930):DOI:10.1211/PJ.2019.20207124

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