You Should Avoid This List of Synthetic Vitamins

List of synthetic vitamins to avoid depicting white tablets on a light blue background by The Healthy RD

This‌ ‌list‌ ‌of‌ ‌synthetic‌ ‌vitamins‌ ‌is‌ ‌here to‌ ‌help‌ ‌you‌ ‌know‌ ‌what‌ ‌vitamins‌ ‌to‌ ‌avoid‌ and which ones to choose. Not surprisingly, ‌factory-made‌ vitamins are ‌definitely‌ ‌less than ideal when‌ ‌it‌ ‌comes‌ ‌to‌ ‌our‌ ‌gut‌ ‌health.‌ ‌ ‌ ‌

In‌ ‌other‌ ‌words,‌ ‌you‌ ‌can’t‌ ‌fool‌ ‌Mother Nature!‌ ‌ ‌

Don’t worry; there are good choices of vitamins out there.

For best gut health, getting a high-quality vitamin supplement made from whole foods can be really beneficial [R].

As a rule of thumb, choose natural food sources of vitamins whenever possible. The bonus is that natural vitamins usually feel much better on your belly than synthetic ones do.

This list of synthetic vitamins and natural vitamins will help you sort out which vitamins to buy and which ones to limit or avoid.

List of synthetic vitamins and natural vitamin alternatives

Here is a breakdown of natural vs synthetic vitamin forms to look for when choosing your next multivitamin supplement:

VitaminNatural formsSynthetic forms
Vitamin ACod liver oil or whole foods, cultured, retinyl acetate from food, retinol Vitamin A palmitate
ThiamineVitamin‌ ‌B1‌ ‌from‌ ‌food‌, culturedThiamine‌ ‌Mononitrate,‌ ‌Thiamine‌ ‌Hydrochloride‌ 
RiboflavinRiboflavin‌ ‌from food or vitamin‌ ‌B2‌ ‌from‌ ‌food‌, cultured, riboflavin-5-phosphate; flavin mononucleotide (FMN)Riboflavin
Niacin‌, ‌vitamin‌ ‌B3‌ ‌from‌ ‌food‌ , cultured, or‌ ‌with‌ ‌coenzymes,‌ ‌niacinamide,‌ ‌nicotinic‌ ‌acid‌‌ 
Niacin,‌ ‌nicotinic‌ ‌acid,‌ ‌nicotinamides‌
Pantothenic‌ ‌acid‌ Pantothenic acid from food, cultured, pantethineD-pantothenic acid, dexpanthenol and calcium pantothenate
Folate‌Methyl folate, folate from food, cultured, 5 MTHF, folinic acidFolic acid
Vitamin B6D-pantothenic acid, dexpanthenol, and calcium pantothenate, pyridoxal-5-phosphatePyridoxine‌ ‌
hydrochloride‌, pyridoxamine
Vitamin B12Vitamin‌ ‌B12‌ ‌from‌ ‌food‌, cultured, ‌or‌ ‌methyl B12‌, adenosylcobalaminCyanocobalamin‌
Vitamin CVitamin‌ ‌C‌ ‌from‌ ‌food‌, cultured, acerola, rose hips, natural liposomal vitamin CAscorbic‌ ‌acid,‌ ‌sodium‌ ‌ascorbate‌, ascorbyl palmitate
Vitamin DCholecalciferol, cultured, ergocalciferol (from mushrooms)Vitamin D analogs (prescription only)
Vitamin EVitamin‌ ‌E‌ ‌from‌ ‌food,‌ ‌cultured, dd-alpha ‌tocopherols,‌ ‌mixed‌ ‌tocopherols,‌ ‌tocotrienols
Vitamin‌ ‌E‌ ‌from‌ ‌food,‌ ‌cultured, d‌l-alpha ‌tocopherols,‌ ‌mixed‌ ‌tocopherols,‌ ‌tocotrienols
Vitamin KPhylloquinone,‌ ‌menaquinone‌, cultured, MK7, MK4Menadione‌

Interpreting vitamin labels

As you can see, the natural forms are primarily food-derived or cultured while the synthetic forms are more likely to have chemical names.

But vitamin names can be similar for both natural and synthetic varieties. This means that you should carefully read the labels. Often, natural vitamins will boast that they are from whole food sources on the front of the packaging, so this gives you a clue.

Niacin, both natural and synthetic, are identical. For this reason, it is difficult to tell if niacin (vitamin B3) is natural.

Don’t fall for names of brands that start with “nature” or “natural.” The ingredients will specify if it contains quality vitamins.

Natural vitamins are also made from cultures of probiotics such as Saccharomyces cerevisiae.

Related: The Best Natural Vitamin Brands + How to Buy Guide

A note about vitamin D

Vitamin D3’s natural form from the sun is cholecalciferol.

However, in supplements, vitamin D is typically made from lanolin which is irradiated to form vitamin D3. Lanolin is a natural substance derived from wool, so this means that most vitamin D3 or cholecalciferol is technically naturally made.

It can also be derived naturally from algae for a vegetarian variety of vitamin D3.

The synthetic forms of vitamin D analogs are sometimes needed for conditions like kidney disease, so the synthetic forms are fine in this case.

Related: Vitamin D Test Cost: Is it Worth the Price?

Why should you avoid this list of synthetic vitamins?

Synthetic vitamins are usually made to help increase the supply of nutrients for the public in a very cheap way.

While the intentions are good, the results aren’t always the same as natural in everyone’s bodies.

They are also often made with chemicals and solvents, such as petroleum, and formaldehyde, which are less than desirable.

Some synthetic vitamins are riskier than others.

Low-risk synthetic vitamins

While it is generally best to get natural vitamins, sometimes the cost is a factor. Some of the synthetic vitamins pose less risk than others, such as thiamine.

Synthetic vitamin C

There really isn’t any known harm in taking synthetic vitamin C.

Yet, it is often derived from GMO sources, so people seeking natural vitamin C will still be best to avoid ascorbic acid.

Synthetic vitamin B12

Synthetic vitamin B12, listed as cyanocobalamin on ingredient labels, has cyanide in it.

However, it is a very trace amount of cyanide. Experts suggest that this amount of cyanide isn’t a concern for health. In fact, vitamin B12 is used to bind cyanide in the body [R].

But, when given a choice, always choose natural vitamin B12.

Synthetic vitamin A

Vitamin A is a naturally occurring vitamin and is identical in both its natural and manufactured form.

For this reason, there is less concern about taking vitamin A palmitate than other synthetic vitamins.

Still, solvents are used in the process, so when you are able, choose natural vitamin A over synthetic vitamin A palmitate.

When to choose synthetic vitamins

There is one important instance where choosing synthetic vitamins is going to be better than natural vitamins.

Allergies to the ingredients.

If you are allergic to any of the foods or ingredients that the vitamins are made from, you should definitely avoid them.

That said, most people are way more likely to tolerate natural vitamin forms and get more out of them for their gut health and overall health.

Related: Are Vitamins HSA Eligible and Tax-Free? How to Know (

Synthetic vitamins to avoid

In the next sections, I will describe the heavy-hitter list of synthetic vitamins to avoid.

Avoid synthetic folate

Probably the most important synthetic nutrient to avoid is synthetic folate, also known as folic acid.

With the advent of gene testing, research shows that around 40 percent of the population can’t metabolize folic acid effectively. Some populations reach up to 90 percent with the gene variant for folate metabolism [R].

People are able to convert natural dietary folates to activated folate in the gut. However, humans have a limited ability to convert folic acid into active folate [R].

This means that folic acid isn’t serving as a vitamin when this occurs.

Folic acid is very similar, but not identical to natural folate. These differences, while minute, make a big difference in how some people’s bodies can use this critical nutrient.

If you have had gene testing and are able to metabolize folic acid, you should safely be able to take folic acid.

But until then, experts in the field of folate recommend choosing natural folate sources instead. These natural forms include methyl folate or folate from whole foods.

For pregnant women, natural folate supplement sources are as safe and effective as folic acid in helping support a healthy pregnancy too [R].

Avoid synthetic vitamin B6

Vitamin B6 is an important nutrient for gut health because it may help support healthy bacteria [R].

Pyridoxine, the synthetic form of vitamin B6, may seem safe, but it likely isn’t. This is because research shows that synthetic vitamin B6 actually reduces the amount of active vitamin B6 in the body [R].

Another issue with synthetic B6 is that it is linked to neuropathy. However, natural forms of vitamin B6 aren’t linked to an increased risk of neuropathy, so natural vitamin B6 is the safest bet.

The best forms of vitamin B6 are listed as P5P, pyridoxal-5-phosphate, or vitamin B6 from foods.

Natural B6 is also better for people who have health conditions, such as epilepsy [R].

Related: 13 Surprising P5P Benefits for Your Health

Avoid synthetic vitamin E

Image of synthetic vitamin E capsules for list of synthetic vitamins post by The Healthy RD

Synthetic vitamin E is very similar, but not identical, to natural vitamin E found in foods.

As it turns out, its subtle differences may have a big difference in how the body responds to it.

Research shows that natural vitamin E is incorporated into our cells at a higher rate than synthetic vitamin E. Additionally, synthetic vitamin E is lost much faster in the urine than natural vitamin E.

But, this isn’t the worst part: the worst part about synthetic vitamin E is that it replaces the natural vitamin E from your foods in cells.

Only natural vitamin E from foods has long-term research to support its therapeutic benefits too.

Vitamin E is important for gut health because it may help to protect the intestinal barrier from toxins and injury [R].

For this reason, it is important to get natural vitamin E instead of the synthetic form.

Related post: Micronutrient Testing: When It’s Worth It to Optimize Health (

List of synthetic vitamins summary

Look for whole-food vitamins in your vitamin supplements to make sure you are getting the best quality vitamins for your digestive tract.

You can print the list of synthetic vitamins table provided in this post and bring it to the store with you so that you know what ingredients to look for too.

In a nutshell, it is best to avoid synthetic vitamins as much as possible because natural forms are usually more effective and safer than their synthetic counterparts.

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body and is shared for educational purposes only. Consult your doctor or healthcare provider before making changes to your supplement regimen or lifestyle.

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