The oral contraceptive pill (OCP) has been in use for over 50 years. Approximately 50–80% of Australian women have used ‘the pill’ at some stage during their reproductive lives. Australia was the second country in the world to have access to it.
The OCP has uses in addition to contraception, such as reducing or ceasing menstruation, decreasing menstrual symptoms, managing dysmenorrhoea, endometriosis, acne vulgaris (common acne) and hirsutism.
There have been adjustments to the doses of active ingredients (progestins and oestrogen derivatives) to try and balance potential adverse side effects with continued efficacy. While this is a whole topic in itself, our article here focuses more on the depletion of certain nutrients when the pill is taken.
Nutrient deficiencies, such as B vitamins, vitamin C, and various minerals, have been observed during use.
Reduced riboflavin (vitamin B2)
Vitamin B2 is necessary for energy production, normal cell function and growth and is critical for proper functioning of the nervous, endocrine, cardiovascular, and immune systems.
Signs and symptoms of vitamin B2 deficiency include degenerative changes in the nervous system, dysfunction of the endocrine system, skin disorders, and anaemia.
Vitamin B6 (pyridoxine)
Vitamin B6 is involved in the metabolism of homocysteine, neurological development, immune function, and formation of haemoglobin. A deficiency of vitamin B6 has been associated with inflammation, anaemia, impaired glucose intolerance, depression and confusion. It plays an important role in metabolism of neurotransmitters, such as dopamine, serotonin, glutamate, and gamma-aminobutyric acid (GABA).
Low plasma levels of vitamin B6 are associated with increased risk of arterial and venous thrombosis.
Reduced folate/folic acid levels
A deficiency of folate results in reduced DNA synthesis and cell division, peripheral neuropathy, and macrocytic anaemia. A deficiency of folate during preconception and during early pregnancy can lead to neural tube defects.
Deficiency of cobalamin (vitamin B12)
In a study of young women (age 25.2 ± 4.2 years) using an OCP, a significantly lower serum vitamin B12 concentration was found. Vitamin B12 is essential for synthesis and regulation of DNA, fatty acid synthesis, and energy production. The mucosa and cervical epithelium have high requirements for vitamin B12. It is also noted that users of the OCP have enlarged cervical and vaginal cells as a result of abnormal folate metabolism.
A vitamin B12 deficiency has been associated with a higher incidence of neurological disorders. I find this very pertinent in clinic, as many health conscious women also reduce their intake of animal protein, therefore sometimes the intake of B12 is also lower.
Reduced vitamin C
Vitamin C deficiency is particularly compounded in OCP users with non-healthy traits, such as poor diet and lifestyle choices. Vitamin C is involved in the synthesis and metabolism of collagen, carnitine and catecholamines, and the metabolism of tyrosine. A deficiency leads to poor wound healing, vasomotor instability, and connective tissue disorders.
Long-term OCP use may increase the risk of reduced calcium levels. Calcium ions affect nearly every aspect of cellular life. Chronic untreated calcium deficiency can cause many severe consequences, including osteomalacia, osteopaenia, and osteoporosis.
Studies have found lower levels of magnesium in OCP patients than in non-OCP users. Magnesium is involved in over 300 enzyme reactions. A deficiency leads to muscle spasms and has been associated with anxiety, cardiovascular disease, type 2 diabetes, and elevated blood pressure.
Studies indicate that OCPs interfere with selenium absorption and a deficiency of selenium has been observed in OCP users. Selenium is an antioxidant,plays a role in the functioning of the thyroid gland, the endocrine system, central nervous system, cardiovascular system, muscle function, and immune response. Deficiency has been linked to cardiomyopathy, osteochondral diseases, oxidative stress, and various chronic degenerative diseases.
Lower plasma zinc levels have been observed in women using the OCP than in non-OCP users. Zinc deficiency has been linked to skin lesions, taste abnormalities, abnormal water balance, decreased immunity, growth impairment, emotional instability, irritability, depression, and impaired cognition and learning. Low intracellular zinc has been found to be associated with oxidative stress, antioxidant defences, DNA damage, and altered DNA repair.
Factors that influence the extent to which the OCP affects the health of a woman depend on her diet, activity level, genetic make-up, other medical history, other medications and ability to absorb nutrients.
While contraceptive choices have given women more freedom to plan a pregnancy and their family, it can have a high cost in terms of other parameters of health, both short and long term.
Considering other contraceptive methods and/or supplying those high demand nutrients with a targeted diet or supplements makes good health sense to support a woman through her fertile age and beyond.