The vitamin B12 craze has been around for years, which is no easy feat in the wellness world where there’s a hot new supplement launch every single week. (Borage oil, anyone?) But the B-vitamin has successfully held its ground as an elite-status ingredient thanks to its many researched-backed benefits.

“B12 is involved in many critical processes in the body such as supporting nerve cell function, making DNA, metabolism, and the formation of red blood cells,” says Jillian Kubala, MS, RD. “And it can’t be made in the body, so it must be obtained through the foods that we eat.” Those foods include animal products like eggs, meat, poultry, and dairy.

If you’re not getting enough from your diet (or you don’t eat animal foods), most experts recommend turning to a B12 supplement, since a deficiency (while rare) can be serious. “Symptoms of a chronic, severe B12 deficiency can include serious side effects such as neurological damage, memory loss, and depression,” Kubala says. “If B12 deficiency progresses, it may lead to neurological disturbances, difficulty balancing, dementia, confusion, and irreversible neurological damage in severe cases.” In the short term, having low levels of B12 could lead to a lack of energy, depressed feelings, anxiety, shortness of breath, and tingling hands and feet.

In other words, if you have an inkling that you may be deficient in B12, make an appointment with your doctor to get your levels checked—stat. Folks who eat plant-based or vegan diets or are over the age of 50 are generally more susceptible to a B12 deficiency. Health conditions like Crohn’s and Celiac disease could also increase the risk.

These are the most important vitamins every woman should consider taking:

But wait, why is B12 so important again? Here’s what you need to know about the all-star vitamin.

What are some important vitamin B12 benefits?

1. It could help with your mood and mental health. We all get a little blue sometimes, but if you’re having a hard time getting through the fog, you might need more B12. “Research shows that having low to low-normal levels of B12 increases the risk for depression,” Kubala says. “Supplementation with B12 may improve symptoms of depression and other mood disorders such as anxiety, especially in those with B12 deficiency or who have low-normal B12 levels.” (It’s something that Lo Bosworth has said majorly helped when addressing her anxiety.)

2. It can improve cognitive performance. Upping your B12 intake may also protect your neurological health. “Studies show that having low levels of B12 may harm cognitive health by accelerating neuron loss and negatively affecting brain function,” Kubala says. “In fact, even low-normal B12 levels may lead to poor cognition.” So if you’re low on the vitamin, taking B12 supplements may help boost your memory and other cognitive functions.

3. It can improve energy levels. Taking B12 supplements can also help reduce fatigue and increase your energy levels, Kubala says. But before you start popping them like candy in place of coffee, note that its effect on energy has only been proven with folks who are deficient in the essential vitamin or have low levels of it. So if you’re good on B12, taking supplements likely won’t give you the added energy boost you’re looking for.

4. It supports healthy fetal development. If you’re pregnant (or trying to get pregnant), you especially need to watch your B12 levels. “B12 is critical for the development of the fetus’s central nervous system,” Kubala says. “The rapid growth and development of the fetus during pregnancy increases vitamin B12 needs drastically.” If you’re not getting enough B12 through your food, you can also take a good prenatal vitamin with B12 in it, Kubala says. But as always, be sure to consult with your doctor to ensure you’re taking the right dose and getting what you and your baby need to be healthy.

How can I increase my B12 intake?

“It’s always best to use a food-first approach to getting the nutrients that your body needs,” Kubala says, so load up your shopping cart with B12-rich foods like salmon, fortified nutritional yeast, and eggs. “That said, taking a B12 or B-complex vitamin is a safe and effective way to increase your intake of B12, especially for those who follow vegan or vegetarian diets or for those at risk of a B12 deficiency.”

Before you start popping pills, be sure that you actually need a B12 supplement. “If you are a healthy omnivore, B12 supplements are likely unnecessary,” Kubala says. Consult your doctor to find out if you do need B12 supplements and what dose is appropriate for you based on your needs.

The recommended dose for adults is 2.4 micrograms per day and 2.6 and 2.8 micrograms for expecting and breastfeeding moms, respectively. “Keep in mind that B12 supplements usually provide doses much higher than the recommended dietary allowance,” Kubala says. “However, being that B12 is a water-soluble vitamin, your body excretes any excess that it can’t use in the urine.” Start with food, and if you think you might need more, talk to your doctor about next steps.

Confused about supplements? Here’s your A-Z guide to the most important ones. And here’s why you should re-consider vitamin K.