osteoporosis
10 interactions related to osteoporosis
prednisone + vitamin d
Glucocorticoids such as prednisone speed up the breakdown of vitamin D and blunt vitamin D-driven calcium absorption at the gut, which contributes to bone loss. Population data link oral steroid use to a higher rate of severe vitamin D deficiency, so vitamin D plus adequate calcium is a standard part of long-term steroid care.
methylprednisolone + vitamin d
Methylprednisolone (a glucocorticoid) speeds the breakdown of vitamin D and weakens vitamin D-driven intestinal calcium absorption. Over continued therapy this lowers vitamin D status and contributes to glucocorticoid-induced bone loss.
amlodipine + calcium
In theory, supplemental calcium could slightly blunt the blood-pressure-lowering effect of calcium channel blockers such as amlodipine, but controlled human data do not show a meaningful effect. Drugs.com flags this as a minor, monitor-only interaction with weak clinical evidence.
risedronate + calcium
Calcium and other divalent cations bind risedronate in the gut and form insoluble complexes, blocking absorption of a drug whose oral bioavailability is already very low. Taking them together can reduce the absorbed amount to subtherapeutic levels and quietly undermine osteoporosis treatment.
alendronate + coffee
Coffee (and orange juice) sharply reduce the absorption of alendronate, an oral bisphosphonate whose baseline absorption is already very low. Taking the tablet with coffee instead of plain water can cut the absorbed amount enough to make the dose ineffective for protecting bone.
prednisone + calcium
Glucocorticoids like prednisone impair intestinal calcium absorption and increase urinary calcium loss, contributing to a negative calcium balance and accelerated bone loss. This is a depletion-and-displacement effect, not a chemical interaction in the gut, and it is why calcium and vitamin D are treated as the foundation of bone protection during long-term steroid therapy.
calcium + magnesium
Calcium and magnesium work together in bone mineralization, muscle contraction, and nerve signaling. They share some intestinal absorption pathways, so very large single doses of one can modestly reduce uptake of the other. A balanced intake of both, weighted toward food, supports bone health better than emphasizing calcium alone.
boron + calcium
Boron is an ultratrace mineral that appears to reduce urinary calcium loss and to support the activity of vitamin D, which governs how much calcium the gut absorbs. In short-term feeding studies of postmenopausal women, adding boron lowered urinary calcium excretion and modestly raised estradiol. The effect is supportive rather than dramatic and is most relevant when boron intake from food is low.
alendronate + calcium
Calcium binds alendronate in the gut and forms an insoluble complex, sharply reducing absorption of an already very poorly absorbed bisphosphonate. Taken together, the calcium can leave the osteoporosis drug clinically ineffective.
caffeine + vitamin d
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.