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Natural vs. Synthetic Vitamins – Why It Matters

author avatar Dr. Eric Berg 08/31/2023

Natural vitamins are extracted from natural food sources such as plants, herbs, and animal products. In contrast, synthetic vitamins are manufactured in laboratories and designed to structurally mimic natural vitamins, minerals, and other nutrients such as amino acids and antioxidants.

More than 98 percent of dietary supplements are made from synthetic nutrients. Not only are these products less effective, but they may also increase the risk of side effects, nutrient deficiencies, and even cancer.

Let’s take a look at the difference between natural and synthetic vitamins and what to look for when choosing a vitamin supplement. 

Dietary supplements

What are natural and synthetic nutrients?

Natural nutrients are essential vitamins or minerals, antioxidants, and other health-promoting compounds that occur naturally in whole foods. 

They are typically extracted by grinding or juicing a food source, followed by dehydrating, which leaves a powdered form that can be incorporated into a pill or capsule. 

In contrast, a synthetic nutrient is produced in a laboratory via chemical reactions to manufacture artificial compounds that mimic the chemical structure of naturally occurring nutrients. 

Watch the video below to learn which synthetic vitamin supplements you should avoid.

How are natural and synthetic vitamins different?

Synthetic nutrients are generally poorly absorbed and less effective than their natural counterparts. They also may pose health concerns and can have side effects if taken for prolonged periods. 

“Many people think synthetic vitamins are the same as natural ones,” says Dr. Berg. “That’s incorrect. There are many key differences, and it’s indisputable that natural supplements have far superior health benefits than synthetic ones.” 

Over half of all US adults take one or more dietary supplements to prevent nutrient deficiencies and promote optimal health. Unfortunately, artificial nutrients are cheap to produce, and almost all supplements available in drug stores and supermarkets are synthetic.

In contrast, extracting vitamins from natural food sources is time-consuming and costly, explaining why supplements with natural ingredients are often considerably more expensive. 


It may be tempting to opt for the cheaper synthetic product. However, you are unlikely to get the health benefits you were looking for in the first place, and you may increase the risk of long-term health issues due to taking supplements with synthetic ingredients. 

Whole food vitamins

Three reasons why natural vitamins are better

You may have heard that natural and synthetic vitamins are chemically identical and, as such, have the same benefits.  

While synthetic nutrients may contain the same basic building blocks as natural ones, their structure and chemical bond formation differ, which significantly impacts how the body can absorb and utilize these compounds. 

Here are three reasons why natural vitamins are better than their synthetic counterparts.

1. More effective  

Natural vitamins are more bioavailable, meaning they are more easily absorbed and utilized by the body than synthetic nutrients.

Unlike artificial nutrients, food-derived vitamins are often bound to other organic compounds, such as amino acids or trace minerals, which act as essential co-factors. 

Co-factors increase the bioavailability and absorption of nutrients by protecting them from degradation and facilitating transport across cell membranes.

In contrast, synthetic vitamins are produced in isolation and lack co-factors, which significantly reduces their bioavailability. This explains why supplements made with artificial nutrients often contain extremely high doses to compensate for the poor absorption of the ingredients. 


2. Free of contaminants and artificial preservatives 

Many synthetic multivitamin supplements are made with a long list of ingredients such as artificial preservatives and sweeteners, bulking agents, and food coloring to increase the shelf-life and enhance color and texture.

Natural vitamins typically don’t contain synthetic additives and have a significantly lower risk of contamination from heavy metals, dioxides, or petroleum.

3. Lower risk of side effects 

Taking natural vitamins has a lower risk of side effects than synthetic vitamins. 

Synthetic products often contain much larger concentrations of nutrients than are naturally found in foods. This can lead to hypervitaminosis—excessive levels of vitamins in the body due to prolonged intake of large doses.  

Individuals with kidney or liver disease often have some degree of impaired detoxification and elimination and are at an increased risk of hypervitaminosis due to synthetic supplements. 

Natural vitamins are typically free of artificial coloring and preservatives, which, in some individuals, can trigger symptoms of sensitivities and allergic reactions such as hives, rashes, nausea, and gastrointestinal issues.  

Watch the video below to discover why natural vitamins are a better choice to promote overall health. 

Is it safe to take synthetic vitamins?

Relying on synthetic vitamins for your intake of vital nutrients may result in vitamin deficiencies.

Not only are synthetic nutrients less effective than natural vitamins, but they are also typically produced using harsh chemicals that aren’t considered safe for human consumption.  

A recent study published in Free Radical Research found that it’s not uncommon to find residues of heavy metals, pesticides, petroleum, hexane, and other environmental contaminants like polychlorinated biphenyls and dioxins in synthetic supplements. 

Long-term exposure to such contaminants is linked to a number of potentially harmful effects, such as neurological and hormonal issues, impaired liver function and immune defenses, and an increased risk of cancer.  

“Synthetic isolates are not the same as natural vitamin complexes in food,” explains Dr. Thiel, research scientist, and nutrition expert, in his study published in Medical Hypotheses. “Humans would not naturally want to eat many of the substances that are used in the manufacturing of synthetic vitamins.”

The majority of artificial vitamins are produced overseas, which makes them a cheap ingredient for supplements, vitamin waters, and fortified foods and beverages such as shakes or vitamin-loaded teas. 

However, it's important to understand that safety regulations and manufacturing standards vary significantly worldwide and that consumers have no insight into the origin, production process, or quality controls of synthetic forms of ingredients. 

 Variety of supplements

Avoid these synthetic vitamins

While it’s best to avoid all synthetic vitamins, this may not always be possible, and in some instances, taking artificial nutrients may be necessary due to specific medical needs, such as vitamin deficiencies.

However, it’s important to remember that synthetic vitamins should only be used under the guidance of a healthcare provider.

Here are common synthetic vitamins that you should avoid whenever possible.

Synthetic fat-soluble vitamins

Fat-soluble vitamins can penetrate into cells, where they regulate gene expressions and cellular functions. 

Because synthetic nutrients often have a different chemical bond formation and may be contaminated, they may trigger unwanted gene expressions and alter normal cellular functioning, which can lead to an increased risk of metabolic disease, cancer, and heart disease.  

Here are four synthetic fat-soluble vitamins to avoid: 

Vitamin A

Retinol palmitate is the synthetic form of vitamin A which is toxic in high doses. This form of vitamin A is particularly problematic for pregnant women as it’s linked to congenital disabilities. 

Vitamin D

Synthetic vitamin D, also known as vitamin D2 or ergocalciferol, isn't as potent and bioavailable as natural vitamin D3. Vitamin D2 is significantly less effective at treating vitamin D deficiency.

There also is some concern that high doses of synthetic vitamin D2 can increase the risk of heart disease and pancreatic cancer. 

Vitamin E

Dl-alpha-tocopherol, a synthetic form of vitamin E, interferes with blood clotting, increases the risk of excessive bleeding, and has been linked to premature death. 

Vitamin K 

Vitamin K3 is the synthetic form of vitamin K. Also known as menadione, vitamin K3, in large doses, can cause liver damage and increases the risk of hemolytic anemia, a blood disorder characterized by lack of oxygen transport and destruction of red blood cells. 

Woman checking supplement labels

Synthetic water-soluble vitamins 

Compared to fat-soluble vitamins that are stored in the body, water-soluble vitamins don’t accumulate, and excess amounts are excreted via the urine. 

While this makes synthetic water-soluble vitamins somewhat safer than fat-soluble ones, it’s still recommended to avoid artificial nutrients and choose whole food vitamins whenever possible.

Here are some common synthetic water-soluble vitamins to avoid:

Vitamin B6

Synthetic vitamin B6, or pyridoxine hydrochloride, may cause neurological damage and sensory issues when taken in high doses or for prolonged periods.

Folic acid

While folic acid can help prevent neural tube defects, there are some potential risks linked to this synthetic form of folate.

Excessive intake of folic acid supplements can mask a vitamin B12 deficiency, which can lead to significant nerve damage if left untreated. In addition, high doses of folic acid can increase the risk of cancer and cognitive decline in individuals with a genetic predisposition

Vitamin B12

The synthetic form of vitamin B12, cyanocobalamin, isn’t very bioavailable and may actually increase the risk of vitamin B12 deficiency. 

Cyanocobalamin contains a cyanide molecule that has been found to interfere with vitamin B12 metabolism and may lead to inadequate circulating vitamin B12 levels.  

Vitamin C

Ascorbic acid, the synthetic form of vitamin C, is significantly less effective than its natural form and doesn’t contain the same range of phytonutrients and co-factors as natural sources of vitamin C, such as citrus fruits or acerola cherries. 

Healthy foods and natural vitamins

The best ways to get natural vitamins and minerals

The best way to obtain essential nutrients in natural form remains to be a nutritious diet incorporating a wide range of nutrient-rich food sources, including organic vegetables, berries, wild-caught game and fish, grass-fed beef and organ meats, and full-fat dairy.  

In addition, it’s essential to avoid foods and beverages such as alcohol, highly caffeinated energy drinks, processed foods, refined carbs, and sugars that deplete the body of nutrients.

However, at times it may not be practical or possible to consume a well-balanced nutritious diet, and it may be necessary to include vitamin or mineral supplements to promote healthy nutrient levels.

Here are some tips to help you choose a natural supplement:

  • Whole food-based—Choose supplements that use natural sources of vitamins and minerals, such as vitamin C from acerola cherries or iron from spinach. 

  • Organic—Choose organic vitamins from food sources that haven’t been exposed to pesticides or other potentially harmful environmental pollutants.  

  • Avoid additives and fillers—Read labels and avoid supplements with unnecessary additives and fillers.

  • Certifications—Look for supplements certified as organic by a third-party organization and produced in GMP-certified US facilities. 

It's important to note that the term "natural" isn’t regulated by the Food and Drug Administration (FDA) and can be used on supplement labels without any specific certification. This can make it challenging for consumers to spot synthetic products. 

A supplement is likely made from synthetic ingredients if it:

  • Is very cheap

  • Contains very large doses, such as 200 percent of the recommended dietary allowance (RDA), of individual nutrients  

  • Lists nutrients as chemical names without indicating a natural food source 

  • Contains fillers, preservatives, and artificial flavors and colorings 

Vegetable capsule

Key takeaways

Compared to synthetic vitamins produced in laboratories, natural vitamins are derived from whole food sources and are more easily absorbed and utilized by the body. 

Synthetic vitamins are cheaper than their natural counterparts but often are contaminated with heavy metals, hexane, and petroleum residues and pose a greater risk of side effects.

Getting all the nutrients we need from the foods we eat isn’t always possible, and taking a good-quality supplement made with natural vitamins derived from whole foods is an excellent alternative to promote good health. 


1. What are synthetic vitamins?

Synthetic vitamins are manufactured in laboratories through various chemical processes. While these artificial nutrients are made to mimic the chemical structure of natural vitamins, they typically have slightly different chemical bond formations. 

2. Do synthetic vitamins function the same as natural vitamins?

Synthetic vitamins and natural vitamins can perform similar functions in the body. However, there are some differences between natural and manufactured vitamins that can affect their absorption, metabolism, and overall effectiveness.

3. What is the difference between natural and synthetic dietary supplements?

Natural vitamins are derived from whole foods such as plants, herbs, and animal products. In contrast, synthetic supplements are manufactured in laboratories.

Natural vitamins are more easily absorbed and generally more potent than synthetic nutrients. In addition, synthetic vitamins pose a greater risk of side effects and may contain potentially harmful chemical residues due to their production processes. 


4. What are examples of synthetic vitamins?

Examples of common synthetic supplements are retinol palmitate (vitamin A), vitamin D2 or ergocalciferol (vitamin D), Dl-alpha-tocopherol (vitamin E), vitamin K3 or menadione (vitamin K), pyridoxine hydrochloride (vitamin B6), folic acid (folate), cyanocobalamin (vitamin B12), and ascorbic acid (vitamin C).

5. How can you tell if a vitamin is synthetic?

There are synthetic versions of most nutrients, and it can be challenging to spot them. However, if a supplement is cheap, contains various artificial fillers, coloring, and flavors, or doesn’t indicate a food source for each nutrient, it’s likely made from synthetic vitamins.  

6. Are synthetic vitamins better than natural ones?

While synthetic vitamins can be beneficial for specific detoxification protocols, they can’t be considered better than natural vitamins. 

Synthetic vitamins are often contaminated with potentially harmful residues and are less effective compared to vitamins from natural foods. In addition, taking some synthetic vitamins such as vitamin A, vitamin D, vitamin K, and vitamin E for prolonged periods may increase the risk of cancer, bleeding disorders, and neurological issues.   

7. Why are natural vitamins better than synthetic vitamins?

Natural vitamins are readily recognized by the body and have a lower risk of contamination and side effects.

In addition, natural vitamins typically are bound to co-factors which increase the bioavailability and absorption of nutrients and facilitate their transport across cell membranes.

8. Are synthetic vitamins good or bad?

Synthetic vitamins can be beneficial if taken under the supervision of a healthcare provider. 

However, long-term intake of synthetic vitamins and minerals has been linked to higher exposure to environmental pollutants and may increase the risk of neurological and hormonal problems, weakened immune function, and increased risk of cancer. 

9. Are multivitamins natural or synthetic supplements?

Unfortunately, most multivitamins are synthetic. Especially cheap multivitamins readily available in drug stores and supermarkets are likely made from artificial ingredients. 

10. Is a natural vitamin more bioavailable than a synthetic vitamin?

Yes, natural vitamins are significantly more bioavailable than synthetic ones. Synthetic nutrients are less readily absorbed.

11. Are natural vitamins worth the cost?

Yes, natural nutrients are worth the cost. Natural vitamins and minerals are more potent and perform the same functions as if they were obtained from whole foods. In addition, natural vitamins are less likely to contain contaminants and don’t pose the same risk of side effects as synthetic vitamins. 


12. What is the best way to get natural vitamins?

While a nutritious diet remains the best option to obtain natural vitamins and minerals, a good quality supplement made from whole food derived vitamins can be an excellent alternative to promote a healthy body.  

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