Probiotics vs Multivitamins

Supermarket and pharmacy shelves are brimming with supplements today. There are many different kinds of supplements available, and marketers have led some people to believe that supplements are the ultimate answer to the problem their doctor couldn’t treat.

While that may be an exaggeration, probiotics and multivitamin supplements are useful in some conditions. If all the different types of supplements confuse you every time you visit the pharmacy, this article will provide some clarity.

Let’s take a look at what probiotics and multivitamins are, how they differ from each other, and who should take them.

What are multivitamins?

Multivitamins — also called multivitamin supplements — are exogenous vitamins that come in many different forms including capsules, tablets, liquid, and powders.

They are the most commonly used supplements in the world, but what do they do?

Well, these supplements provide the body with vitamins, which are chemicals required for a wide range of chemical reactions in the body. All vitamins are found in our diet and in healthy people, multivitamin supplements may not be very useful.

However, in certain diseased states, the body becomes depleted of a vitamin, which can lead to unpleasant signs and symptoms depending on the vitamin that’s deficient.

There are two main categories of vitamins — fat-soluble and water-soluble. The main fat-soluble vitamins are vitamins A, D, E, and K. The main water-soluble vitamins include vitamins B and C. Some vitamin supplements may contain only a single vitamin — like vitamin D — while others contain a varied mix of different vitamins.

Multivitamin supplements may also contain additional micronutrients like zinc and iron, which are essential for healthy metabolism. 

Here’s a list of the most important functions of some vitamins and what happens when you become deficient in them: 

  • Vitamin A is required for good vision, healthy skin, and a functioning immune system. Deficiency can lead to night blindness, dry and scaly skin, and immune dysfunction.
  • Vitamin B9 is needed for red blood synthesis. Deficiency leads to anemia, which can cause fatigue. Pregnant women deficient in vitamin B9 can have children with nervous system defects.
  • Vitamin B12 is also needed for red blood synthesis. Since B12 is found in animal-derived foods, vegetarians and older adults are at high risk for developing a deficiency. Patients who have undergone stomach surgery can also develop B12 deficiency, which presents as anemia and central nervous system problems like numb hands and feet. All these groups can benefit from a vitamin B12 supplement.
  • Vitamin C is needed for healthy blood vessels and a deficiency can present with bleeding gums and easy bruising.
  • Vitamin D is needed for strong bones, and older adults and postmenopausal women may benefit from a supplement because they are prone to fractures due to osteoporosis.
  • Vitamin K is required for normal blood clotting and a deficiency can lead to abnormal bleeding.

If you feel you have any of the above symptoms, a vitamin deficiency might be at play. Before starting a multivitamin supplement, you must report your symptoms to your doctor because some vitamin deficiencies are diagnosed via blood tests.

You should know that while multivitamin supplements are generally safe, an excess of vitamins can actually be harmful for you.

This is especially true for the fat-soluble vitamins because they get stored in body fat and are not easily washed out. For example, excess vitamin A can lead to liver enlargement, joint pains, and fetal abnormalities in pregnant women.

A vitamin excess can build up if you take a supplement along with a healthy, well-balanced diet. So it’s a good idea to always consult a doctor before trying out a new supplement.

What are probiotics?

In simple terms, probiotics supplements are bacteria. You may think it’s dangerous (and weird) to consume bacteria, but there are many bacteria found naturally in your gut.

Over 500 species of bacteria are found in the healthy gut and these are required for the normal maintenance and functioning of the digestive system. This is called the gut microbiome, and the goal of probiotics is to support and increase the number of healthy bacteria in the gut.

Unlike vitamins, probiotics don’t get absorbed in the blood. Instead, they stay in the gut and restore the balance of bacteria there.  

While it’s unlikely that a healthy individual would benefit from a probiotic supplement, they have been shown to be beneficial in conditions like: 

  • Diarrhea
  • Irritable bowel syndrome (IBS)
  • C difficile infection, which often occurs as a result of antibiotic use and can manifest as diarrhea
  • Inflammatory bowel disease — this includes Crohn’s disease and ulcerative colitis
  • Food allergies
  • Vaginal and urinary infections

You may not know this but just like the gut, the vagina is also home to a large colony of bacteria, which is needed for normal functioning and infection prevention. And just like the gut, bacterial balance in the vagina may get abnormal, leading to vaginal infections.

Probiotics supplements may restore vaginal bacterial balance and treat symptoms but the evidence for their effectiveness is not enough for them to replace conventional treatment yet.

Some people confuse probiotics with prebiotics. Unlike probiotics, prebiotics don’t contain bacteria. But just like probiotics, they increase the number of healthy bacteria in the gut by acting as food for them.

You should also know that just like vitamins, probiotics can also be obtained from natural foods. These include:

  • Kimchi
  • Yogurt
  • Kombucha
  • Miso
  • Sauerkraut 

And just like with multivitamins, make sure you consult your doctor before trying out new probiotic supplements.

Probiotics and vitamins are not tightly regulated by the FDA

You should be aware that unlike drugs, supplements are not tightly regulated by the FDA. If you don't purchase your supplements from a well-known, research-oriented supplement company, you may end up with a poor-quality and ineffective product.

Make sure to check the bacterial strain of a probiotic supplement before buying it and ask your doctor if it’s effective for your condition. Also check the expiration date, since expired probiotics supplements contain ineffective, dead bacteria.

For vitamin supplements, read the label carefully. Many vitamin supplements contain iron, which may not be suitable for individuals with hemochromatosis. Iron overload may lead to GI problems and vomiting in healthy people too.



If you have IBS, Casa de Sante low FODMAP certified probiotic and prebiotic combo and low FODMAP multivitamins are quality and effective products which are excellent choices.

Medically reviewed by Onikepe Adegbola, MD PhD

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