Research

Hormonal

High supplemental intake of vitamin D (≥800 IU/day) and calcium (≥1,200 mg/day) is associated with a significantly lower risk of developing type 2 diabetes in women, with the combined high intake reducing risk by 33% compared to low intake.

For women looking to potentially lower their risk of type 2 diabetes, aiming for high intakes of Vitamin D and Calcium via supplements may be beneficial. Specifically, targeting at least 800 IU of Vitamin D and 1,200 mg of Calcium daily was associated with a 33% lower risk in this study. Note that this benefit was observed with supplements, not just dietary sources, and the study focused on women.

ModerateSupportsMEDIUM confidence
A combined daily intake of ≥1,200 mg calcium and ≥800 IU vitamin D was associated with a 33% lower risk of type 2 diabetes with RR of 0.67 (0.49 – 0.90) compared with an intake of <600 mg and 400 IU calcium and vitamin D, respectively.
Anastassios G. Pittas et al. · Diabetes Care · 2006

Why this rating

Large prospective cohort (Nurses' Health Study) with long follow-up, but observational nature limits causal inference compared to RCTs.

Source

Vitamin D and Calcium Intake in Relation to Type 2 Diabetes in Women

Anastassios G. Pittas et al. · Diabetes Care · 2006

DOI 10.2337/diacare.29.03.06.dc05-1961

cohort · n=83779Cited 836×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →