1 in 4 women in Australia aged 18 to 49 are using the oral contraceptive pill (also known as “the pill” or OCP) at one point or another in their reproductive lives.

Whilst most women are on the pill to avoid pregnancy, what happens when you do want to pregnant? Is it as simple as stop the pill and everything is exactly like it was and you’re ready to get started on growing your family?

Well, maybe not from a nutritional perspective.

Turns out the pill can deplete women of essential nutrients, which means you may have some catching up to do before you start actively trying for a family. Or if you are currently taking the pill and would like to be proactive keep on reading.

But first, how does the pill even work to prevent pregnancy?

How does the Oral Contraceptive Pill Work?

For those of you whom are not familiar, the pill works by taking a combined oestrogen and progesterone pill 21 days in a row at the same time everyday, and then 7 days of a sugar pill when you get your “period”, or a withdrawal bleed. The blood that is shed is due to the removal of hormones rather than what would occur in a regular menstrual cycle.


The hormones help prevention ovulation (an egg being released) by suppressing the release of the hormones that trigger this process. The other way it works is to prevent sperm getting past your cervix to the uterus and fallopian tubes by thickening your cervical mucus.

So basically, no egg release, no possibility of fertilisation but also the addition of a potential extra barrier for those swimmers to get up there!

Now that we know the basics of how the pill works, let’s get to the nutrients it is depleting!

FYI, this topic is on the radar of World Health Organization (WHO) as a really relevant topic and should be receiving more attention.


Zinc is an essential mineral that I have discussed many times before when it comes to both sperm and egg health, so it’s obviously important for fertility health! Studies have shown that women who take the OCP have lower levels of zinc in their blood, which has been a long-standing research point since the 1960s and has continually been confirmed (Palmery et al., 2013). It is thought the reason why is because of changes in the zinc absorption and losses meaning there may be a higher dietary need for zinc amongst women who take the OCP.

Key dietary sources of zinc are:

  • Oysters, crab & other shellfish
  • Meat
  • Legumes & beans
  • Cashews & other nuts
  • Seeds
  • Eggs
  • Quinoa & other wholegrains


Magnesium is an essential mineral important for the production of energy and helps with over 300 reactions in the body. It can help with muscle relaxation, sleep, and bone health too. Research has shown multiple times that magnesium in the blood can be reduced by oral contraceptive pills, and it is thought that the increased risk of blood clots on the oral contraceptive pills is partially due to the change in the calcium to magnesium ratio (Palmery et al., 2013).

Researchers have proposed that magnesium supplementation during the period of oral contraception should be considered (PLEASE discuss this with your doctor before you start taking any new supplements).

Key dietary sources of magnesium include:

  • Green leafy veggies
  • Fruit (figs, avocado, banana, raspberries)
  • Nuts & seeds
  • Legumes
  • Other vegetables (peas, broccoli, cabbage, green beans, artichoke, asparagus, brussel sprouts)
  • Seafood


Selenium is one of those minerals that is really hard to know how much you’re getting in your diet as it fluctuates based on the selenium content of the soil of where the produce you eat is grown. Selenium is important for helping antioxidants work better in the body, as well as a role in the function of the thyroid.

Studies have shown that the oral contraceptive pill may be interfering with selenium absorption in the body (Heese et al., 1988).

Key dietary sources of selenium:

  • Brazil nuts
  • Pork
  • Beef
  • Turkey
  • Chicken
  • Fish & shellfish

B vitamins

B vitamins are a complex made of B1, B2, B3, B5, B6, B7, B9 and B12 that are essential for our body to get enough of each and every day as they are water-soluble, meaning they are lost via our sweat and urine. B vitamins help with energy formation and also cell health as well as a wide variety of other functions.

Some of the B vitamins that may be lower when a woman is on the pill include:

  • Folic acid (vitamin B9) – obviously important for early pregnancy, so when transitioning off the pill and you’re trying to conceive, it’s really important you give yourself a few months of taking a prenatal supplement that contains folic acid to ensure you do not start off with a nutrient deficiency. Studies reveal that the pill may be impairing folate metabolism and studies from the 1960s have shown that women taking the pill have poorer folate status based on their bloodwork (Palmery et al., 2013). Get amongst those leafy greens and fortified grain foods to boost your daily intake from food too!
  • Riboflavin (vitamin B2) – turns out women of reproductive age can be at risk of vitamin B2 deficiency, found in milk, eggs, lean meats and the pill can be making this worse according to studies dating back to the 1970s (Newman et al., 1978). Bonus, getting enough riboflavin can help reduce the headache intensity, frequency, and duration – a common side effect of the pill (Zencirci, 2010)!
  • Pyridoxine (vitamin B6) – a study from the 1960s showed that women taking a combination oral contraceptive pill had evidence of vitamin B6 deficiency and that was later confirmed with a large-scale and more recent US study showing that 75% of women taking the pill had significantly reduced B6 intake (Morris et al., 2008). Key dietary sources are protein foods, bread, cereals, and veggies.
  • Vitamin B12 – a critical vitamin for cell division and repair, turns out women taking the pill have lower blood levels of vitamin B12 compared to non-pill taking women, it might work similarly to the folate metabolism disturbance (Palmery et al., 2013).

Vitamin C

Vitamin C, another water-soluble nutrient, famous for its immune promoting benefits, is also an antioxidant critical for cell health and collagen formation for skin and gum health.

There may be some differences in the vitamin C status of women taking the pill, but eating plenty of fruit and veggies can easily overcome the risk of any kind of vitamin C deficiency which is rare with a healthy diet which contains an abundance of vitamin C!

So, what’s the best way forward when it comes to eating well to prevent vitamin and mineral deficiencies when taking the pill? Speak to an Accredited Practising Dietitian with an interest in women’s health to guide you on your way whether you’re planning for a family soon or not for a while yet, it’s important to get on top of it earlier rather than later.

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