Objectives: Vitamin D has immune-modulating effects and may protect against the development of Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA).
Methods: We identified incident cases of SLE and RA among 186,389 women followed from 1980-2002 in the Nurses’ Health Study and Nurses’ Health Study II cohorts. We excluded subjects with non-confirmed SLE or RA by medical record review, and those who failed to return questionnaires. Semi-quantitative food frequency questionnaires assessed vitamin D intake from food and supplements. We used cumulative-updated total energy-adjusted dietary exposures for each two year cycle. Relationships between vitamin D intake and incident SLE and RA were examined in age-adjusted and Cox proportional hazards models, adjusted for confounders. Results were pooled using meta-analysis random effects models.
Results: We confirmed 190 incident cases of SLE and 722 of RA with dietary information. Increasing levels of vitamin D intake had no relationship to the relative risk of developing either SLE or RA.
Conclusions: Vitamin D was not associated with risk of SLE or RA in these large prospective cohorts of women.
- rheumatoid arthritis
- risk factor
- systemic lupus erythematosus
- vitamin D