Is Birth Control Messing with Your Nutrition?

Oral contraceptives are prescribed beyond preventing pregnancy, for reasons such as
  • To regulate menstrual cycles
  • Provide some relief for pain during menstruation
  • Acne
  • Ovarian cyst prevention.
  • PMS and PMDD relief
  • Endometriosis management
  • Menstrual migraine relief

However, there are many drawbacks of the contraceptive pill which may be affecting your future fertility. In this blog I am going to focus on nutrition depletion.

Research has demonstrated the use of oral contraceptives may be significantly affecting bodily levels of many essential vitamins and minerals. 1-5

Here are 5 essential nutrients commonly depleted by the pill

• Magnesium

• Zinc

• Folic acid

• Vitamin B12

• Vitamin E


The pill and oestrogen therapy has demonstrated a depletion in serum magnesium levels, causing a potential deficiency of this essential mineral. 6,7 This is concerning for most females in where dietary magnesium intake is already low, not to mention a 21st century lifestyle that quickly uses up magnesium stores such as poor sleep, high-intensity exercise, chronic stress, and high intake of caffeine, sugar, and processed foods. 7-12

Magnesium has many benefits which have been supported by research such as supporting energy, sleep, mood, and hormone balance. Given the body’s widespread need for magnesium, low dietary intake in addition to the continual drain on the body’s stores, it is particularly concerning that the contraceptive pill may be depleting levels even further.

Furthermore, magnesium depletion alters the calcium to magnesium ratio which may affect blood coagulation.13 The deficiency in magnesium may contribute to the thromboembolic complications associated with oestrogens.6,7 Therefore, it is worth taking magnesium supplementation in addition to your diet when taking the oral contraceptive pill. 


Lower plasma zinc levels have been observed in research dating as far back as 1968 14,15 in addition to more recent studies confirming this finding too. 16-20

Zinc is an essential trace element, used as a cofactor for more than 300 different enzymes, used in every cell, organ, bone, tissue, and fluid of the body.  Zinc is involved in immune and skin health and is important in supporting reproduction. The World Health Organisation (WHO), states the global prevalence of zinc deficiency is a surprising 31%.

The changes which occur as a result of increased oestrogen from the oral contraceptive pill may lower blood zinc levels and also increase the amount of zinc used by bodily tissues. 21-22 When these alterations occur, the need for dietary zinc increases. 20

Although not all research demonstrated a reduced level of zinc, the majority indicated that oral contraceptives, to include lower doses, have a negative effect on the nutritional status of this mineral. 16,20,23-31 Additionally, a decrease in zinc, selenium, phosphorus and magnesium in women taking oral contraceptives was found in a recent systematic review 32 which had been associated to the duration of contraceptive use.

Therefore, when oral contraception is recommended by your health professional, supplementing zinc may be useful and is best supplemented with copper due to both minerals being antagonists, which means they compete for binding sites in the body. Excess zinc can lead to a copper deficiency and vice versa.

Folic acid

Studies have demonstrated a potential reduction in blood folate levels. 33-37. One recent systematic review and meta-analysis concluded, due to reduced blood folate concentrations associated with the use of oral contraceptives, it is necessary that women of a childbearing age to continue the use of folate supplementation whilst using the contraceptive pill. 38

Folic acid is necessary within the first 4 weeks of pregnancy in order to prevent neural tube defects. Due to the folate-depleting effects of the oral contraceptive, in 2012 there was the introduction of contraceptives that were fortified with folate to help reduce the risk of neural tube defects in pregnancies that occurred during use or shortly after the discontinuation of oral contraceptives.39,40

Some evidence has shown an increase in the rate of cervical dysplasia to cervical cancer progression and that folic acid may slow or reverse this dysplasia.41,42

Recent studies recommend all women of childbearing age taking the oral contraceptive pill should supplement with folic acid. It is recommended to take the body-ready form of 5-methyltetrahydrofolate (5-MTHF) of folic acid as some people are genetically less able to convert folic acid into this active form, and therefore is less effective. Supplementing with active 5-MTHF form of folic acid bypasses the need for conversion and therefore reassures folate stores are being replenished.

Vitamin B12

The depletion of vitamin B12 in women using oral contraceptives has been found in many studies, compared to non-users .20, 43-52 In addition to folic acid, low maternal B12 status is also considered to be a standalone risk factor for neural tube defects. 53

Vitamin B12 has many functions, such as

  • Supports the blood to carry oxygen
  • Essential for healthy nerves and DNA synthesis
  • Supports the elimination of toxins   

Animal products are a rich source of vitamin B12 and are the only vitamin that can’t be reliably supplied by a varied wholefood plant-based diet.

one recent systematic review demonstrated oral contraceptives have been found to deplete vitamin B12, therefore vitamin supplements might be beneficial when taking oral contraceptives.54.55

Vitamin E

Vitamin E has many positive health benefits, to include

  • Antioxidant
  • Healthy skin
  • Immune function support
  • Cardiovascular support

Research demonstrated that the oral contraceptive had increased markers of oxidative stress and decreased levels of vitamin E in the blood. A further study found a significant rise in the clotting activity of blood platelets when taking the oral contraceptive pill, naturally accompanying decreased blood levels of vitamin E. 56-58 Research found, supplementing with vitamin E increased vitamin E blood levels and had shown a decrease in the clotting activity of platelets.59

Daily supplementation may help to support improved levels of key nutrients

Research has shown that oral contraceptives can deplete blood levels of many essential vitamins and minerals, in addition to the above, therefore if you are required to take the oral contraceptive pill you may benefit from supplementing your diet with a daily multivitamin & mineral to support these possible negative effects.


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