More than 100 million women worldwide prevent unintended pregnancy with combined oral contraceptives, also called COCs or "the pill." With correct and consistent use, this form of birth control can be over 99 percent effective. Many COC users wonder about its potential interactions with other drugs, supplements and substances in food, such as vitamin C. Tell your doctor if you are taking any other prescription or over-the-counter medications or supplements, including vitamin C. Ask any questions regarding the pill and vitamin C.
How COCs Work
COCs contain versions of the female reproductive hormones estrogen and progesterone. COCs suppress ovulation, the monthly release of an egg cell from the ovary, thus mimicking pregnancy. They also thicken mucus from the cervix so sperm cells cannot travel into the uterus.
Functions of Vitamin C
Unlike most animals, with exceptions such as guinea pigs, humans cannot make their own Vitamin C, also called ascorbic acid or ascorbate. Because vitamin C is essential to life, humans need to eat it in foods or supplements. Vitamin C facilitates iron absorption from plant foods. It is vital to healing from wounds and other immune system functions. It is also an antioxidant, a kind of chemical compound known to help protect against cellular damage and thus diseases like cancer from ultraviolet light and pollutants, including cigarette smoke.
The Question of Interaction
"Family Planning: A Global Handbook for Providers" lists specific drugs, mostly anti-seizure medications and antibiotics, that interact with COCs. It does not mention Vitamin C. The Recommended Dietary Allowance of Vitamin C has not been increased for women on COCs. Drugs.com does state that vitamin C and birth control pills can interact but does not elaborate.
Scientific findings at the time of publication were mixed and inconclusive. Researchers have seldom studied the question of vitamin C-oral contraceptive interaction since the 1970s and 1980s. The most commonly-used dosages and formulations of oral contraceptives have changed dramatically since that time. Some women on COCs have reduced vitamin C and elevated copper levels in their bloodstreams. Ceruloplasmin, the protein that carries copper --- a necessary dietary mineral --- through the blood, has the ability to break down vitamin C. While estrogens may stimulate the body to create more ceruloplasmin, women on oral contraceptives do not absorb more copper, according to a 1992 study from the American Journal of Clinical Nutrition.
Good Nutrition
If you are on the pill, you might still wish to be extra careful to eat a well-balanced, nutritious diet with plenty of vitamin C-rich foods, such as citrus fruits, potatoes, peppers, broccoli, tomatoes, cantaloupe and strawberries. Females ages 14 to 18 need 65 mg per day and adult women 75 mg, except during pregnancy and breastfeeding, when requirements definitely need to increase, according to the National Institutes of Health. Adults should not consume more than 2,000 mg daily or they risk gastrointestinal problems and a toxic overstorage of iron. Ask your doctor or nutritionist about the best diet plan for you.
References
- "The American Journal of Clinical Nutrition"; Effects of Age and Sex on Copper Absorption, Biological Half-Life and Status in Humans; Phyllis E. Johnson, et al.; November 1992
- "Colorado State University Extension"; Nutrition and Oral Contraceptives; J.E. Anderson; December 2010
- Drugs: Vitamin C
- Family Planning: A Global Handbook for Providers
- Herb, Nutrient, and Drug Interactions; Mitchell Bebel Stargrove, et al.; 2008
- Office of Dietary Supplements, National Institutes of Health: Vitamin C
