Vitamin absorption depends on many complex factors, including form, diet, and health. The best form of vitamin supplement for you depends on your health and needs.

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Capsules, tablets, liquids, and powders — many different types of supplemental vitamins are available today from a range of vitamin brands.

Researchers have long begun studying how different nutrients are absorbed and used in the body.

Although more research is needed, scientists believe a variety of factors affect nutrient absorption, including dietary fat intake, interactions between foods and vitamins, and even stress.

If you’re looking to get the most out of vitamin supplements, there are several ways to improve absorption.

This article reviews everything you need to know about which vitamin supplements offer the best absorption and how to maximize vitamin absorption.

Vitamin supplements are available in a variety of forms, including gummies, pills, liquids, and powders.

Research, such as this 2022 study, has looked into whether liquid supplements absorb more easily than forms like powder or tablets. However, more studies are needed to support this claim.

A 1982 study on vitamin C supplements suggests they absorb equally well in powder, chewable tablet, and non-chewable tablet forms. However, the absorption of vitamin C supplements in slow release forms is unclear.

Although the bioavailability — meaning the ability of a nutrient to be absorbed and used by the body — of some nutrients are fairly well understood, research into the uptake, absorption, and bioavailability of other nutrients in humans is still at an early stage.

More research is needed to understand how different forms of vitamin supplements are absorbed in the body.

Some vitamin manufacturers add coatings to pills to enhance flavor or shelf life. A 2019 article on vitamin D supplements found that coatings may affect the dissolution or absorption of a vitamin.

Water-soluble vs. fat-soluble vitamins

In addition to a vitamin’s form, many other factors affect absorption. For example, water-soluble vitamins absorb differently than fat-soluble vitamins, and others are stored in the body.

There are two main types of vitamins: water-soluble (all eight B vitamins and vitamin C) and fat-soluble (vitamins A, D, E, and K).

Water-soluble vitamins dissolve in water and are generally not stored in the body. Excess amounts exit the body through urine.

These vitamins must be consumed regularly to prevent shortages or deficiencies in the body. However, one exception is vitamin B12, which can be stored for years in the liver.

Fat-soluble vitamins dissolve in fats, which then travel through the small intestines and are eventually distributed through the bloodstream. Excess amounts of these vitamins are stored in the body’s liver, fatty tissue, and muscles for later use.

According to a 2021 review, other factors that can affect the absorption of nutrients include:

  • interactions with other foods or vitamins
  • dietary fat intake
  • alcohol
  • age

However, the review studied the absorption of food sources of vitamins, not vitamin supplements. More research is needed on the absorption of vitamin supplements to understand which forms absorb more easily than others.

What is bioavailability?

Bioavailability is the degree or rate at which a substance, such as a medication, becomes completely available to its intended biological destination.

In the context of vitamins, bioavailability refers to the amount of vitamins (nutrients) in ingested food that is absorbed by the body and used at the cellular level.

Research suggests many complex factors affect the bioavailability of vitamin supplements, including form, binding agents, diet, and health conditions.

A particular vitamin supplement may have a range of bioavailabilities. In addition, the bioavailability for an individual may vary based on factors such as health and diet.

Here are some steps you can take to improve vitamin absorption.

Pair complementary nutrients

Certain nutrients help each other absorb. For example, fat-soluble vitamins are better absorbed when consumed with a small amount of healthy fat, such as olive oil, avocado oil, or almond butter.

Additionally, plant-based sources of iron, such as beans, lentils, and nuts, require vitamin C for absorption. Pairing them with vitamin C-rich foods or vitamin C supplements may improve absorption.

Maintain a healthy gut

Your gut plays an important role in the absorption of nutrients from the food you eat. Maintaining a healthy gut may help make sure your body absorbs essential vitamins and minerals.

You can keep your gut healthy by:

You may also want to consider taking probiotics, which may have beneficial effects on gut health.

Reduce stress

Research suggests chronic stress may increase the body’s metabolic needs as well as the use and excretion of nutrients. This may lead to low micronutrient levels in the body.

Some options to reduce stress include:

  • maintaining a healthy diet
  • getting regular exercise
  • having good sleep hygiene
  • practicing mediation or deep breathing
  • signing up for mental health counseling

Talk with your doctor about effective ways to reduce stress. They can work with you to develop a stress management plan based on your health and individual needs.

Consider reducing or avoiding alcohol

Alcohol consumption may interfere with the absorption of nutrients, including water-soluble and fat-soluble vitamins. Frequent alcohol use can also lead to malnutrition.

Consider limiting or avoiding alcohol consumption to make sure your body properly absorbs essential nutrients.

What vitamin supplements are good for absorption?

The best form of vitamin supplements for you depends on your individual needs. For example, if you have difficulty swallowing capsules or tablets, you may prefer a liquid vitamin.

More research is needed to understand how the body absorbs different vitamin supplements.

Which vitamin is hardest to absorb?

Vitamin B12 requires the help of a protein called intrinsic factor for normal absorption. Some people lack this protein and may need injections or high dose supplements of vitamin B12.

Other common vitamin and mineral deficiencies include vitamin B6, iron, vitamin D, and vitamin C. Factors that are associated with these deficiencies include certain health conditions, diet, pregnancy, race, and ethnicity.

What two vitamins should not be taken together?

Long-term consumption of excessive zinc can lead to copper deficiency. To prevent copper deficiency, the U.S. Food and Nutrition Board recommends a tolerable upper level intake of 40 milligrams per day of dietary and supplemental zinc for adults.

According to the National Institutes of Health (NIH), some reports suggest high intake of vitamin C may reduce vitamin B12 and copper levels. However, additional studies have not supported these conclusions.

What is the most bioavailable form of vitamin A supplement?

Vitamin A supplements are available in two main forms: preformed vitamin A (found in foods from animal sources such as meat, fish, and dairy products) and provitamin A carotenoids (found in plant products such as green leafy vegetables).

According to the NIH, the most bioavailable form is preformed vitamin A. The absorption of preformed vitamin A supplements ranges from 70–90%, while the absorption of provitamin A beta carotene ranges from 8.7–65%.

Although researchers are studying the absorption and bioavailability of nutrients, more research is needed to understand the absorption of vitamin supplements in various forms.

Many online reports claim that certain forms of vitamins absorb more easily than others. But a broad consensus in the scientific community is lacking.

Some research suggests pairing vitamins, maintaining good gut health, and avoiding alcohol may improve absorption of nutrients. However, this research has focused on food sources of vitamins rather than vitamin supplements.

The best form or type of vitamin for you depends on your individual needs and preferences. Most people can get all the nutrients they need by eating a healthy, balanced diet.

If you’re interested in taking vitamin supplements, talk with a doctor about the benefits and risks as well as a safe dosage.