Birth Control Affects The Levels Of These Important Nutrients

It may not come as a huge surprise that certain fluctuations in reproductive health, like menstruation or pregnancy, can affect the nutrient levels in the body. (For example, if you or the person you meal prep with has their period, it might be a good night to cook some steak to compensate for any menstruation-related iron loss.) 

The same can be true for women who use certain forms of hormonal birth control. There’s some evidence that taking birth control may affect the body’s nutrient absorption, potentially influencing levels of zinc, B vitamins, and other vitamins and minerals in your system. It may still be true that your chosen form of birth control is right for you right now, but you might want to be proactive about stocking your body on a few key nutrients.

If you or your partner takes hormonal birth control, read on to learn more about how it impacts nutrient status—and how to adjust your nutrition or supplement routine accordingly.

• ABOUT OUR EXPERTS: Kecia Gaither, M.D., M.P.H., F.A.C.O.G., is a physician double board-certified in OB/GYN and Maternal Fetal Medicine and the director of Perinatal Services and Maternal Fetal Medicine at NYC Health + Hospitals in the Bronx, NY. Maggie Michalczyk, R.D.N., is a registered dietitian based in Chicago.  

Why does birth control affect your nutrient levels? 

“A body of scientific evidence suggests that oral contraceptive use can deplete certain nutrients in the body,” says Kecia Gaither, M.D., M.P.H., F.A.C.O.G., a physician double board-certified in OB/GYN and Maternal Fetal Medicine and the director of Perinatal Services and Maternal Fetal Medicine at NYC Health + Hospitals in the Bronx, NY. The impacts, of course, can vary from person to person.

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In many cases, the mechanism here is that hormonal changes resulting from taking hormonal contraceptives—like the birth control pill, the birth control shot (Depo-Provera), or a hormonal IUD—may lead to changes in nutrient absorption, she says. Beyond shifts in hormonal balance caused by these medications, other lifestyle-related factors including your diet and other medications you take can also affect nutrient absorption, adds Maggie Michalczyk, R.D.N., a dietitian based in Chicago.  

What vitamins and minerals Does Birth Control affect? 

It’s important to note that vitamin and mineral deficiencies are not guaranteed if you start birth control, Gaither says. However, deficiencies in the following key vitamins and minerals can crop up after starting hormonal birth control:

• B vitamins (including folate): Studies have previously shown that birth control methods, including the oral contraceptive pill and the Depo-Provera shot, may decrease levels of B vitamins—which are crucial for energy and brain function—in the bloodstream. 

• Vitamin C: Your body may have difficulty absorbing high levels of vitamin C while on birth control, Gaither says. (That said, taking high amounts of vitamin C won’t render your contraception ineffective.) 

• Vitamin E: Your vitamin E levels might decline if you’re taking oral contraceptive pills. The vitamin is essential for eye health, and may also be essential for a healthy uterine lining.

• Magnesium: Some research suggests that hormonal contraception increases the body’s excretion of magnesium and may lead to lower levels of the mineral (which is important for regulating sleep, helping muscles relax, and more).

• Selenium: A Nigerian study found that selenium levels were lowest in people who had contraceptive implants, like Nexplanon, followed by those with hormonal IUDs and then those taking oral contraceptive pills. Selenium supports thyroid health and reproductive cell health.

• Zinc: According to the same Nigerian study, people using hormonal contraception may also have low levels of zinc, which is an essential mineral for immune function.

• Calcium: Birth control use in adolescents could potentially lead to slightly lower bone density, per 2020 research. 

• Iron: If you take birth control pills, you may end up with lighter periods, meaning you’ll lose less iron. However, some IUDs may contribute to heavier periods, which could deplete iron levels. 

How To Get Enough Of These Nutrients While On Birth Control

If you’re overwhelmed by the thought of falling short on the nutrients above, take a beat. First of all, you can get ample amounts of them through your diet with a little extra care. For example, meat is a good source of B vitamins and iron, Michalczyk says.

That said, people who have certain health conditions or eat a particular diet might need to supplement to get levels up (and keep them there), Gaither says. For instance, if you’re vegan or vegetarian and take oral contraception, you might need more support in the B vitamin and iron departments. “As B vitamins are crucial for energy production, women can often experience deep fatigue and lack of energy when low,” says Michalcyzk. If you don’t eat meat or animal products (which are good sources of these nutrients), you should be aware of this and consider supplementing, she says.

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To get a clear picture of your nutrient status—and which vitamins and/or minerals you may need to supplement with—visit your healthcare provider. They can take a detailed health history to better understand potential dietary shortcomings and recommend blood testing to evaluate various nutrient levels, Michalcyzk notes. Together, these tools will offer a better sense of where you might be falling short—and the kinds of diet and supplement changes you might require.

In many cases, a few diet tweaks can go a long way. For example, if you’re short on calcium, you can incorporate extra calcium-rich foods like Greek yogurt, almonds, broccoli, and leafy greens into your diet, suggests Michalcyzk. 

Supplementation may also be an effective strategy. For example, if you have symptoms of a B12 deficiency, such as fatigue and lack of energy, a supplement might be necessary to get you back into good standing, Michalcyzk explains. The same goes for low iron; taking a supplement can help prevent conditions like anemia.

Your best bet is to coordinate with your healthcare provider and make a combination of dietary changes and supplement additions to ensure you stay stocked on these important vitamins and minerals.