supplementation
6 interactions related to supplementation
oral contraceptives + vitamin b6
Combined oral contraceptives lower pyridoxal 5'-phosphate (the active form of vitamin B6) by altering tryptophan metabolism and increasing B6 turnover. Long-term pill users have lower B6 status than non-users, which may contribute to mood symptoms in some women.
prednisone + calcium
Glucocorticoids like prednisone impair intestinal calcium absorption and increase urinary calcium loss, contributing to negative calcium balance and accelerated bone loss. This is a depletion-and-displacement effect, not a chemical interaction in the gut.
methotrexate + folate
Methotrexate works by inhibiting dihydrofolate reductase, depleting active folate and causing GI, mucosal, and hepatic side effects. Folic acid supplementation reduces those side effects by 26-77% without compromising efficacy, but must be timed correctly to avoid blunting the drug's action.
oral contraceptives + magnesium
Several studies have shown that combined oral contraceptive use is associated with lower serum magnesium levels, possibly through estrogen-related shifts in intracellular and extracellular distribution. Low magnesium can contribute to fatigue, premenstrual symptoms, and may modestly elevate venous thromboembolism risk in pill users.
smoking + vitamin c
Smoking increases oxidative stress and accelerates the metabolic turnover of vitamin C, lowering plasma and leukocyte ascorbic acid levels. The NIH Food and Nutrition Board officially recommends that smokers consume an additional 35 mg of vitamin C daily above the standard RDA.
methylprednisolone + vitamin d
Methylprednisolone, like other glucocorticoids, is associated with increased catabolism of 25-hydroxyvitamin D and impaired vitamin D-mediated intestinal calcium absorption. Long-term use contributes to vitamin D deficiency and accelerated bone loss.