Oral Contraceptives (Birth Control Pill): What It Depletes and How to Replenish

Estrogen in OCP increases tryptophan metabolism via the kynurenine pathway, dramatically increasing B6 demand. B6 deficiency is the most consistent nutrient depletion in OCP users.

Rose et al. (1973) — classic study; Lussana et al. (2003) — confirmed elevated homocysteine and B6 deficiency in OCP users

Depression, anxiety, irritability, PMS worsening, nausea, elevated homocysteine

OCPs reduce folate absorption and increase urinary folate excretion. Critical risk: women who become pregnant shortly after stopping OCPs may have depleted folate — the key nutrient preventing neural tube defects.

Steegers-Theunissen et al. (1993) — significantly lower red cell folate in OCP users

Elevated homocysteine, neural tube defect risk if conception follows OCP cessation

OCPs reduce B12 serum levels, likely via altered binding protein levels rather than malabsorption.

Webb et al. (2003) — lower B12 in OCP users; Lussana et al. (2003)

Fatigue, mood changes, elevated homocysteine

Estrogen increases magnesium uptake into red blood cells and bone, lowering serum magnesium.

Seelig (1993) — estrogen-driven magnesium redistribution documented

Muscle cramps, headache, PMS symptoms, sleep disturbance

OCPs raise serum copper while lowering zinc — they have opposing effects on the zinc/copper ratio.

Prasad et al. (1978) — elevated copper, reduced zinc in OCP users

Immune suppression, skin issues, hair loss, acne (zinc deficiency)