Is the Pill Causing Nutrient Deficiencies? A Nutrition Consultant Explains

It’s time to get informed.

By Edie Horstman

Unbeknownst to most, science proves there’s a link between birth control and vitamin deficiency. If you ask a menstruating woman if she’s on the birth control pill, there’s a high chance (as in, over 60%) that her answer is yes. And while women take birth control for a variety of personal reasons, the side effects are relatively hush-hush. Turns out, the birth control pill can affect your body’s ability to absorb nutrients. In turn, this causes changes in mood, energy levels, and neurological functions.

Unsurprisingly, this can have long-term impacts including improving your cellular health before you start actively trying to conceive. Today, we’re uncovering the truth about birth control and vitamin deficiency. Let’s get the facts straight.

Feature image by Kristen Kilpatrick.

woman sitting on a rock in a seated position_birth control and vitamin deficiency
Image by Riley Reed
Edie Horstman
Edie Horstman

Edie is the founder of nutrition coaching business, Wellness with Edie. With her background and expertise, she specializes in women’s health, including fertility, hormone balance, and postpartum wellness.

Why do women take birth control pills?

The answers vary. For most, birth control pills are a convenient and easy way to prevent pregnancy. They’re also used to help treat symptoms and manage certain medical conditions. Think: PCOS, PMDD, and endometriosis. Lastly, research shows they can offer other benefits, like reducing acneeasing period pain, and mitigating PMS symptoms. And of course, they give people who menstruate more agency over their bodies.

How does the birth control pill work?

Before we get into vitamin deficiencies, it’s important to explain how the pill works. Depending on the type of synthetic hormones, birth control pills prevent pregnancy by either stopping or reducing ovulation, thickening cervical mucus to keep sperm from entering the uterus, or thinning the lining of the uterus so that a fertilized egg is less likely to attach.

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Image by Michelle Nash

Spoiler Alert: You Aren’t Getting a Real Period on the Pill

If this is news to you, trust that you’re not alone. Most women have no idea that on birth control, you don’t have a true period. Whether you bleed once a month, every few months, or notice spotting on occasion, you’re not having an actual period. Reason being, the bleeding that occurs when you’re on the pill is not the same as a menstrual period.

Your “period”—on the pill—is called withdrawal bleeding. This refers to the withdrawal of hormones in your specific pill, and in your body. The drop in hormone levels causes the lining of your uterus to shed. In turn, you bleed. Understanding this is very important. After all, having normal cycles (not withdrawal bleeds) is extremely important for your overall health—not just now, but in the future.

More on understanding your menstrual cycle, here.

woman sitting on her white bed_birth control and vitamin deficiency
Image by Michelle Nash

Side Effects of Taking Birth Control Pills

Despite the proclaimed benefits of birth control, there are downsides. For example, the link between birth control and vitamin deficiency. More on that, shortly. It’s not uncommon for some women to experience side effects when they start taking the pill. Unfortunately, we’re still waiting for the science to catch up. At any rate, we do have some data, pointing to the following potential side effects:

  • Nutritional deficiencies
  • Breast tenderness or swelling
  • Headaches
  • Irritability or moodiness
  • Nausea
  • Spotting between periods (abnormal menstruation)

Talk to your doctor if you experience any of these side effects. Or, let’s work together to take a more holistic approach to preventing pregnancy, balancing your hormones, and more.

Woman eating a healthy salad
Image by Michelle Nash

Vitamins and Minerals At Risk for Deficiency

When it comes to nutrient deficiencies caused by birth control, the research speaks volumes. Clinical studies show that the main vitamins and minerals at risk of deficiency—while on the pill—include B vitamins, vitamin C, vitamin E, magnesium, selenium, and zinc. Below are potential telltale signs of vitamin deficiency for each nutrient, as well as foods and supplements to boost your levels.

B Vitamins (Including Folate)

B vitamins are crucial, especially during early pregnancy. Studies reveal that the pill may be impairing folate metabolism, along with other B vitamins. Other research, dating back to the 1970s, shows that the pill increases a woman’s risk of vitamin B2 deficiency. Foods with folate—and other B vitamins—include dairy, eggs, meat, leafy greens, and fortified breads and cereals.

Signs of deficiency: anemia, fatigue, dry skin, neuropathy, brain fog, depression, and weakness.

Vitamin C

The birth control pill is shown to cause decreased levels of ascorbic acid, aka, vitamin C. Be sure to load up on citrus, bell peppers, strawberries, tomatoes, and cruciferous veggies.

Signs of deficiency: fatigue, irritability, easy bruising, and suppressed immune system.

Plate of stuffed bell peppers
Image by Suruchi Avasthi

Vitamin E

Vitamin E is a powerful antioxidant, required for proper immune system function. Unfortunately, the pill decreases Vitamin E plasma content in healthy women. You’ll find vitamin E in plant-based oils, nuts, seeds, fruits, and vegetables.

Signs of deficiency: muscle weakness, immune system deficiency, and neurologic issues.


Magnesium is an essential mineral, important for the production of energy. It also helps with over 300 reactions in the body. Research shows that magnesium in the blood can be reduced by birth control pills. Dietary sources of magnesium include green leafy veggies, fruit, nuts and seeds, legumes, and seafood.

Signs of deficiency: cramping, aches, and fatigue.

Flat lay of walnuts, oil, and citrus
Image by Michelle Nash


Selenium is important for helping antioxidants work better in the body and plays a key role in the function of the thyroid. Studies indicate that the birth control pill may be interfering with selenium absorption in the body. Dietary sources of selenium include Brazil nuts and animal protein.

Signs of deficiency: thyroid issues, weakness, fatigue, skin/hair issues.

Bowl of Spring Rice Salad with Fresh Herbs Eggs and Avocado - Vegetarian Protein Packed Salad
Image by Suruchi Avasthi


Zinc is an essential mineral, especially when it comes to sperm and egg health. Long-term studies show that women who take birth control pills have lower levels of zinc in their blood. You can get zinc through seafood, animal protein, legumes, beans, cashews, eggs, and quinoa.

Signs of deficiency: immune system deficiency, skin and hair issues.