Written by Felicity Harvie
The oral contraceptive pill (OCP) is used by 50-80% of Australian women at some stage throughout their reproductive lives. Yet, the pill can deplete women of many essential nutrients.
Most women use the pill to prevent pregnancy, but can you simply stop taking the pill when you decide to try for a baby?
Nutritionally speaking, it’s probably not the best option (1).
Here is a list of 6 nutrients commonly depleted in women taking the OCP
All B vitamins, including B6, play many important roles including energy production, mood stabilisation and skin and liver health. Vitamin B6 plays an important role in the production of neurotransmitters including serotonin and GABA that can affect our moods (2).
Great sources of B6 include meat proteins as well as whole grains such as brown rice and oats.
Blood levels of B6 have been found to be significantly lower in those women who take the OCP versus those who don’t (1).
It has been suggested that low B6 levels can contribute to some of the side effects of taking the pill including depression, lethargy and fatigue. Low B6 levels can also have an impact on morning sickness during pregnancy as well as risk of low moods and depression in the postpartum period (3).
Vitamin B12 is involved in over 100 daily functions in body. It essential for the synthesis and regulation of DNA, for nervous system health and energy production (1).
It is found in abundance in most animal products and is one of the only vitamins that can’t be reliably supplied by a wholefood plant-based diet.
A randomised control trial found that women who used took the OCP had consistently lower serum B12 concentrations independent of their dietary intake (4). Urinary excretion and absorption of B12 were normal, however the total binding capacity of the vitamin in serum is reduced and the glycoprotein that protects B12 from stomach acid is also reduced (3).
B12 deficiency is associated with a higher level of neurological disorders including depression and anxiety (1). Low levels of vitamin B12 during pregnancy are considered to be a risk factor for neural tube defects (1).
Folate is well known for its importance during pregnancy for supporting neural tube development, neurological health, growth and development. Folate deficiency has also been associated with mood disorders including depression and anxiety (3).
Folate can be found in a wholefoods diet high in fruits, vegetables, nuts, seeds and legumes. Some great sources include spinach, avocado, beans and lentils.
Women who take the OCP have lower levels of serum folate as the pill may interfere with absorption of accelerate excretion of folate in the body (3).
Alongside vitamin B12, folate is particularly important during preconception and pregnancy for the prevention of neural tube defects (1).
Magnesium is an essential mineral important for energy production and is involved in over 300 enzyme reactions in the body. Deficiency of this mineral is associated with anxiety, cardiovascular disease, type 2 diabetes and high blood pressure (1).
Some great foods that are high in magnesium include leafy green vegetables, nuts and seed, legumes and dark chocolate.
Oestrogen therapy, including the use of OCP lowers serum magnesium levels and can cause deficiency of this essential mineral. This is as a result of increasing uptake by bones and soft tissues resulting in an inverse relationship between the two (3).
Selenium is important for functioning of the reproductive system thyroid health, nervous system function as well as other major functions within the systems of the body. Deficiency is associated with depression and anxiety, oxidative stress and various chronic degenerative diseases (1).
Some great sources of selenium include brazil nuts, eggs and wild-caught fish.
A cross-sectional randomised study of women using the OCP found that mean serum selenium levels in those women were significantly lower than controls (3). Good selenium levels are important before conceiving for thyroid function. Low levels of thyroid hormones can increase the risk of infertility and miscarriage (5)
Zinc is a component of at least 300 metalloenzymes that catalyse more than 50 different physiological reactions in the body. Deficiency has been linked to skin lesions, taste abnormalities, decreased immunity, growth impairment, depression, and impaired cognition and learning (1).
Good sources of zinc include nuts and seeds, eggs, seafood and oysters.
Lower plasma levels of zinc have been found in those women taking the OCP compared with those who aren’t. This is likely due to changes in absorption, tissue turnover or excretion (3).
Zinc is a common nutrient that is depleted for women during pregnancy and the postpartum period and have been shown to affect maternal mental health and wellbeing. Lower zinc levels have also been associated with longer times to achieve pregnancy (6).
Research demonstrates that oral contraceptives can deplete blood levels of many essential vitamins and minerals. A few have been highlighted here but there are many more. This emphasises the importance of preconception care to optimise nutrient status and eating a good quality wholefoods diet whilst taking the OCP. The research also highlights the benefits of nutritional supplementation whilst on the pill (3). Get in touch with your health practitioner about what sort of supplementation would be right for you and your circumstances.
Co-authored by Felicity Harvie.
1. Fenasse R, McEwen B. Impact of the oral contraceptive pill on health and nutritional status. J Aust Tradit Med Soc. 2019;25(4):197–203.
2. Sato K. Why is vitamin B6 effective in alleviating the symptoms of autism? Med Hypotheses [Internet]. 2018;115(April):103–6. Available from: https://doi.org/10.1016/j.mehy.2018.04.007
3. Wakeman MP. A Review of the Effects of Oral Contraceptives on Nutrient Status, with Especial Consideration to Folate in UK. J Adv Med Med Res. 2019;30(2):1–17.
4. McArthur JO, Tang HM, Petocz P, Samman S. Biological variability and impact of oral contraceptives on vitamins B6, B12 and folate status in women of reproductive age. Nutrients. 2013;5(9):3634–45.
5. Qazi IH, Angel C, Yang H, Pan B, Zoidis E, Zeng CJ, et al. Selenium, selenoproteins, and female reproduction: A review. Molecules. 2018;23(12):1–24.
6. Grieger JA, Grzeskowiak LE, Wilson RL, Bianco-Miotto T, Leemaqz SY, Jankovic-Karasoulos T, et al. Maternal selenium, copper and zinc concentrations in early pregnancy,and the association with fertility. Nutrients. 2019;11(7):1–12.