Omega-3 fatty acids are crucial to good health. That’s especially true for women who are trying to conceive, currently pregnant, breastfeeding or just trying to get their hormones back on track. But while essential fatty acids are so, well, essential, we cannot produce them on our own, so we must consume them through diet and supplementation. Research shows that the best source of omega-3 fats is fatty fish, followed by walnuts, eggs, pumpkin seeds and freshly ground flax seeds. Yet eating a serving of each of these foods per day may not give us all the amount that our bodies need. And while fish oil is a great way to supplement, cod liver oil may be the healthier choice for couples who’ve decided to start a family.

Here are 5 reasons you should start taking cod liver oil before getting pregnant.

  1. It can boost fertility. Omega-3 fatty acids — DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) — are known to provide a wide range of health benefits — from a lower risk of heart disease to improvement in cholesterol. They can also reduce inflammation, balance your hormones, increase blood flow to the uterus, up the production of egg white cervical mucus, improve sex drive and even support proper sperm production. Cod liver oil thus fosters a vaginal environment that is favorable to conception and provides you with all the ingredients you need to potentially get pregnant faster.
  1. It’s lower in mercury and other heavy metals. Mercury is an element that collects in oceans, lakes and streams; and in high quantity, it can be detrimental to the nervous system. So you want to avoid fish that is at risk of high mercury content. Cod, especially Atlantic cod, is a deep-water fish that tends to have much lower mercury levels , making it safer for women who are trying to conceive or who are pregnant. It’s also important to choose brands that adhere to strict extraction and distillation processes so that their oil remains clean and toxin free. A few of the brands I know are free of heavy metals and contaminants are Green Pasture’s Blue Ice Fermented Cod Liver Oil, Rosita Extra Virgin Cod Liver Oil, and Carlson’s Cod Liver Oil.
  1. It’s rich in vitamin A. Vitamin A boosts the immune system and promotes good skin, bone and vision health. But it doesn’t stop there: it’s also essential for reproductive health. Vitamin A helps follicles mature properly and promotes cervical fluid that is more abundant and more nourishing to the sperm. It also helps regulate hormones. There are two types of vitamin A: preformed vitamin A (retinol or retinoid), which you can find in animal products; and provitamin A (carotenoid), which are found in fruits and vegetables. During pregnancy, it’s important not to get too much preformed vitamin A — the kind that is in cod liver oil — because it can cause serious risks to your unborn baby, including birth defects. So talk to your doctor to figure out how much vitamin A you can and should take.
  1. It’s a great source of vitamin D. The human body produces vitamin D in response to skin being exposed to sunlight. You can otherwise get this “sunshine vitamin” through food and supplements. But according to a Harvard study, 1 billion people are low in vitamin D, which can cause short- and long-term health effects — one of them being the imbalance of sex hormones. Vitamin D can help women who suffer from PCOS and can boost progesterone and estrogen production, both of which are responsible for regulating menstrual cycles, therefore upping your chance of successful conception.
  1. It’s also good for the baby. During pregnancy, essential fatty acids are important to your baby’s brain, nervous system, eye and heart development. Studies also show that babies of women who consumed cod liver oil are at lower risk for juvenile type 1 diabetes. What’s more, having a sufficient level of DHA and EPA acids can help prevent complications like preeclampsia, premature birth and miscarriage. Finally, if you plan on breastfeeding your child, taking cod liver oil can continue to contribute to your baby’s brain development. And since cold liver oil is rich in vitamin D and A, it can boost immunity and keep baby’s bones strong.

Personally, I take one teaspoon daily of the Green Pasture’s Fermented Cod Liver Oil as the fermentation process makes this oil easier to digest (and it shouldn’t repeat on you). To hear more about my favorite supplements for moms-to-be, check out my “Top Three Fertility Vitamins” video.

* The tips in this article have been adapted from my book, Yes You Can Get Pregnant: Natural Ways to Improve Your Fertility Now and Into Your 40s.