1 interaction related to VDR
Higher caffeine intake is weakly associated with lower vitamin D status. In cell studies caffeine reduces vitamin D receptor (VDR) expression in bone-forming cells, and a large NHANES cross-sectional analysis links higher caffeine intake to a modestly greater chance of low serum 25-hydroxyvitamin D. The effect is small and matters most for people who already have low vitamin D, low calcium intake, and high bone-loss risk (for example, postmenopausal women). It is not an absorption-level interaction, so there is no need to separate the timing of a vitamin D supplement from coffee.
