B vitamin deficiencies slowly settle in over time. People who are deficient might grow so accustomed to the symptoms, they hardly notice a problem is going on at all! Fatigue, brain fog and weakness is commonplace.

It’s important to listen to your body—it’s trying to tell you something’s wrong, and that very well could be a lack of B vitamins. Take a look at what causes vitamin B deficiencies and what you can do about it.

Lack of nutritional foods in the diet

A B vitamin deficiency could simply mean you’re not consuming enough of the vitamin B complex. Part of a balanced diet requires eating foods that meet the daily requirements for B vitamins. There are many different types of B vitamins, and falling short of just one can lead to a B vitamin deficiency. For example, the average adult woman should consume 2.4 micrograms of vitamin B-12 per day. However, the recommended dose of biotin is closer to 30 micrograms. Check with your doctor to see how much of the vitamin B complex you need every day.

In order to consume enough B vitamins, you have to pick foods with high nutritional value. People with vitamin B deficiencies often eat a diet consisting of fatty, processed foods. Fast food restaurants serve burgers, fries and shakes with high concentrations of fat, oil and sugar. Such food offers very few vitamins and minerals, especially not B vitamins.

Dietary restrictions

The vitamin B complex is primarily derived from animal products. The most common sources include meat, eggs, cheese and milk. Vegans often have a difficult time getting enough B vitamins, particularly B-12, in their diet because dietary restrictions prevent them from eating these foods. As a result, it’s not uncommon for vegan diets to cause a B vitamin deficiency. Vegetarians and people with lactose sensitivities might become deficient for the same reason.

People who can’t eat animal products must find an alternative source for the vitamin B complex. Otherwise, they run the risk of developing a B vitamin deficiency. Luckily, animal products aren’t the only foods containing B vitamins. You can also find them in nuts, legumes and leafy vegetables, although they’re not as concentrated as animal products.

Problems with nutrient absorption

Health problems involving the digestive tract negatively affect a person’s ability to absorb B vitamins. For example, someone might be less efficient at absorbing B vitamins if they have a surgery that removes part of the stomach. Conditions that damage the small intestine’s lining also make it difficult to sustain adequate vitamin B levels.

Certain substances can lower the rate at which your body absorbs B vitamins, too. Excessive alcohol use prevents the body from getting enough of any vitamins or minerals, not just the vitamin B complex. Alcohol may curb a person’s appetite altogether, which means their body has limited access to nutritional foods. Prescription drugs can also hinder nutrient absorption. If you’re taking medication, check to see if B vitamin deficiency is a possible side effect.

How to put B vitamins back in your diet

The good news is B vitamin deficiencies are rarely permanent. For most people, incorporating supplements or vitamin B-rich foods is enough to achieve a balanced diet.

Here are a few options for people with B-vitamin deficiencies:

• Plant-based foods: Animal products aren’t the only sources of B vitamins. Vegans and people with lactose sensitivities should increase their intake of plant-based options like legumes, seeds and leafy greens. Each offers varying concentrations and B-vitamin types, so focus on the foods that are best for your specific deficiency. Of course, people who don’t have dietary restrictions can also increase their consumption of eggs, dairy and lean meats.
• Fortified cereal: If you can’t eat animal products, plant-based foods might not be enough to meet the daily B vitamin requirements. Many breakfast cereals are fortified with various types of B vitamins to supplement diets lacking the vitamin B complex. Keep in mind that not all cereals are fortified with B vitamins—or are even healthy, for that matter. Read the ingredients list to confirm a cereal’s vitamin B content.
• Vitamin B supplements: The easiest way to boost your B vitamin levels is by taking a daily supplement. One capsule can provide a whole day’s worth of B vitamins. However, supplements are no substitute for whole foods with high nutritional value. They’re meant to go hand-in-hand with a balanced diet to plug gaps left by dietary restrictions or other challenges.

A vitamin B deficiency isn’t the end of the world. With any luck, adding nutritious foods to your diet will be enough to rectify the problem. It’s also important to remember that B vitamin deficiencies can sometimes signal an underlying issue. A physician can monitor your vitamin B levels and recommend the most appropriate treatment if necessary.