Synthetic Vs. Natural Vitamins: Why It Matters & How to Tell the Difference

Heather Dessinger

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Natural supplements in ceramic bowls

Have you ever found yourself standing in front of a store shelf, picking up bottle after bottle of “natural” vitamins and flipping them over to read the label? If the answer is yes, you may already know that many so-called natural vitamins actually use significant amounts of synthetic ingredients in their formulas.

How does that even happen, and does it matter? We’ll dive into those answers today – plus how to spot the synthetic stuff and natural forms to look for – and in a follow-up post I’ll explain what I use and why.

So, what’s the difference between natural and synthetic vitamins?

Natural can mean a lot of things depending on who you ask, but for the purposes of this article we’ll define things this way:

Natural, bioavailable supplements – Derived from whole foods such as acerola cherry, these supplements contain a variety of phytonutrients that work together to support vitality in ways that we are still discovering. They can be in capsule or pill form (dried, ground herbs for example) or a liquid form such as herbal tincture extracts.

Synthetic supplements with low bioavailability – Usually made in a lab, these supplements are typically isolated nutrients. They tend to be chemically identical to their natural counterparts, but not molecularly. If it’s been awhile since you picked up a chemistry textbook, when something is chemically identical it has all the same ingredients, and when something is molecularly identical it has all the ingredients arranged in exactly the same pattern.

Manufactured (some would say synthetic) supplements with high bioavailability – In this category there are two kinds of supplements: Those that were created in a lab and those that were refined from natural ingredients into isolated nutrients. The important thing to know about them is that they are both chemically and molecularly identical to the way they are found in nature.

In other words, although they are not “natural” in the sense that they were manufactured or processed to the point that they don’t resemble their whole-food origin, they do use the natural, optimally bioavailable form of the nutrient.

4 Concerns With Synthetic Supplements

Unfortunately, just because a synthetic vitamin is chemically (and even molecularly) identical to the natural form does not automatically mean it will have the same effect. Two hormones – oxytocin and pitocin (synthetic oxytocin) – are identical, but they have different effects on the body.

The same can be said for some synthetic supplements. Here’s why:

1. They don’t use natures “secret recipes”

Let’s say your friend bakes amazing carrot cakes and she walks through the door with a beautiful baking tin in her hands. Your mouth is already watering by the time she lifts the lid to reveal . . . carrots, eggs, baking soda and all the other ingredients that go into her recipe. All the right ingredients are there, but they’re not in a form that you or I would recognize as carrot cake.

The same things can happen with certain synthetic nutrients. Just like we immediately recognize carrot cake when all the ingredients are assembled in the right way, our bodies recognize nutrients when they’re structured in a particular way.

Nature has it’s own “secret recipes” that combine nutrients in an optimal way, and there is so much innate wisdom about these “formulas’ that we are still discovering. (1)

When the constituents are isolated and used separately they have less therapeutic benefit. Carrots alone do not count as carrot cake, and isolated nutrients aren’t the same as their whole-food form.

For example, it was once thought that a medicinal herb had an “active constituent” that was the sole source of its therapeutic benefits. Over time, though, we’ve learned that there are usually several supporting constituents that amplify the therapeutic effect of the primary constituent. When isolated, it often becomes far less effective.

2. Our bodies don’t always know how to use them

In nature, vitamins have either a right (D) form or left (L) form called optical rotation. In plain English, that means they’re chemically identical, but instead of being structurally identical they’re mirror images of each other. (Think right and left handed gloves.)

Some nutrients are “right-handed,” while others are “left-handed.” For example, vitamin C occurs in nature as l-ascorbic acid but not d-ascorbic acid.

Some nutrients naturally occur in both forms, but our bodies are only able to use one form. The amino acid arginine is an example: Both l-arginine and d-arginine exist in nature, but only the l-form is considered to be biologically active. (2)

To understand why one mirror-image works but not the other, imagine you’re trying to put together a puzzle and you find two pieces that fit together. That’s what happens when a vitamin attaches to a cell receptor site – the cell locks onto it because it fits just right.

Would the same piece work if you flipped it over and tried to put it in place? Nope, because although it’s the exact same piece it’s not oriented correctly.

That the issue with some synthetic nutrients. Even when they’re chemically identical to what’s found in nature, they’re not always structurally. When that’s the case, our bodies can’t use them well.

Take vitamin E, for example. In this study, researchers found that natural vitamin E was absorbed twice as efficiently as the synthetic version.

In another study, natural vitamin K was compared with synthetic K1, and researchers concluded that just 1/4 the dose of the natural form was more effective than the synthetic form.

3. They may clog cell receptor sites

Poor absorption is not the only problem, though. When the wrong form is given to our bodies, it may clog the receptor sites that could be used by truly bioavailable nutrients.

Folic acid, for example, is a synthetic compound that many people (especially those with the MTHFR mutation) cannot use efficiently. When consumed, it attaches to receptor sites that are then blocked for use by a more bioavailable form such as methylfolate.

4. They come in unnaturally high doses

Manufacturers often use higher doses to try to overcome the low absorption issue, but there are downsides to that approach.

Research suggests that because our bodies don’t metabolize folic acid (which is synthetic) well, it may build up in the body and increase the risk of cancer. (3) (4)

Another study found that 1 gram of daily synthetic vitamin C impaired mitochondrial function and reduced athletic performance. (5)

There also one more thing to consider: Some nutrients – calcium and magnesium, for example – compete for absorption, so taking excessive amounts of one can throw off another. This can happen even when the lab-created supplement uses the natural, bioavailable form.

How do I know if my supplement is natural or synthetic?

Here are a few things to look for:

If the label says it’s made from 100% plant or animal sources, it’s natural

If it just says “natural” or “whole food-based,” it may have natural ingredients that are spiked with synthetic vitamins to make it appear more potent. Remember, natural vitamins are better absorbed than synthetic ones so we don’t need megadoses. However, high dosages seem like a good idea to many consumers and marketers use that to their advantage.

An example a 100% plant based supplement would be ground turmeric in a cellulose capsule. Cod liver oil (without synthetic vitamin A or D added in) would be a 100% natural animal product.

If a vitamin is listed in “dl” form, it’s synthetic

For example, natural vitamin E is d-alpha-tocopherol and synthetic vitamin E is dl-alpha-tocopherol.

If the label says “derived from,” dig deeper

“Labels often proclaim ‘natural’ B vitamins, derived from yeast. But companies manufacturing yeast add laboratory-synthesized B vitamins to the food fed to the yeast during its growth, and then fortify the yeast further with additional B vitamins once it has grown. This allows the production of yeast of any B-vitamin potency desired, which is then used to formulate vitamin pills labeled ‘B vitamins derived from yeast.’” (

This can happen with other nutrients as well, but I don’t think that every supplement which uses “derived from” wording is using this kind of approach. For me, seeing that phrase is a sign that I need to talk to the manufacturer and ask some questions.

If it lists isolated nutrients like “vitamin C” or “ascorbic acid,” it’s most likely synthetic

If a product that claims to have vitamin C lists a whole food ingredient such as rosehips or acerola cherry powder on the label, it’s natural.

However, as I mentioned above, some supplements are refined into isolated nutrients from natural sources in a way that I feel comfortable with. More on when I opt for nutrients in this category below.

All mineral supplements are natural

Even when synthesized, all mineral supplements are sold in forms that are found in nature. However, some are better absorbed than others – oxides and chlorides tend to have low absorption rates. Also, as is true with other supplements, they are often coated in hydrogenated fats such as magnesium stearate and stearic acid which inhibit absorption.

Are synthesized or isolated nutrients ever a good idea?

I think so. If one of my kids develops a urinary tract infection, you can bet I’m breaking out the d-mannose. Yes, it’s an isolated nutrient and in general I opt for nutrients that have all of their natural co-factors, but d-mannose is an exception. To get enough from food, my children would have to eat a ton of fruit, which would increase their sugar intake and potentially make the UTI worse.

In cases like the one I just mentioned, using the “natural” or bioavailable form of a nutrient – regardless of how it was manufactured – can be incredibly helpful. Of course, whenever I use a supplement like this as an intervention I also look for ways to address the root cause of the issue going forward.

Although they are isolated nutrients, lab-created supplements that are in their “natural” or bioavailable form can be helpful for targeted supplementation. By that, I mean targeted supplementation can help to correct a deficiency while the individual works on lifestyle factors to address the root cause of that deficiency.

Common Names of Natural & Bioavailable Vitamins

Most of the time if a particular vitamin is listed on a label, it’s an isolated nutrient that has been added to the formula. However, there are exceptions. The fish oil I buy does not have synthetic vitamin A and D added in, but because consumers want to know exactly how much of these vitamins it contains they specify that on the nutritional label.

This list is not exhaustive, but hopefully you’ll find it helpful in identifying whether the nutrients in your supplements are optimally bioavailable.

  • Vitamin A (Retinol) – As I mentioned in this article on eating healthy during pregnancy, nutrition labels often say that a food has “X” amount of Vitamin A, but what they really mean is that it contains carotenoids such as beta-carotene. Unfortunately beta-carotene is not biologically active, and therefore not the same as the bioavailable form of Vitamin A (retinol) found in animal products. Most of us do not possess enough of the enzyme needed to efficiently convert beta-carotene into bioavailable Vitamin A – in fact, this study found that only about 3% is converted, and about 45% of adults can’t make the conversion at all. (source 1source 2)
  • Vitamin B1 (Thiamine) – Thiamine pyrophosphate; Thiamine triphosphate
  • Vitamin B2 (Riboflavin) – Riboflavin-5-phosphate; Flavin mononucleotide
  • Vitamin B3 (Niacin) – Nicotinamide (adenine dinucleotide)
  • Vitamin B5 (Pantothenic Acid) – Pantethine Pyridoxine
  • Vitamin B6 (Pyridoxine) – Pyridoxal-5-phosphate
  • Vitamin B9 (Folate) – Folinic acid; 5-methyl tetrahydrofolate
  • Vitamin B12 (Cobalamin) – Methylcobalamin; Adenosylcobalamin
  • Choline – Phosphatydlcholine
  • Vitamin C – The  l-ascorbic acid found in an orange is both chemically and molecularly identical to the synthetic version. However, I personally believe that the benefits of vitamin C are strongly tied to the co-factors found in whole food forms, so I opt for food and whole-food supplements such as dried acerola cherry.
  • Vitamin D – D3 (However, supplementing with vitamin D may not have all the same benefits as sunshine)
  • Vitamin K2 – menaquinone-7 (MK-7)

Wondering what natural supplements I use?

This article was inspired by a question from Kirsten, who asked what supplements I give my kids. That’s a great question, and I’m working on a post about what I use and why that I will publish soon. Stay tuned!

Have a question about natural supplements? Please post it in the comments below!

This article was medically reviewed by Madiha Saeed, MD, a board certified family physician. As always, this is not personal medical advice and we recommend that you talk with your doctor.

natural supplements

Article sources:

1. Liu, RH (2003) Health benefits of fruit and vegetables are from additive and synergistic combinations of phytochemicals. Retrieved from

2. Drugbank, supported by the Canadian Institutes of Health Research. D-Arginine. Retrieved from

3. Sweeney, MR et. al. (2007) Folic acid fortification and public health: report on threshold doses above which unmetabolised folic acid appear in serum. Retrieved from

4. Ebbin, M et. al. (2009) Cancer incidence and mortality after treatment with folic acid and vitamin B12. Retrieved from

5. Gomez-Cabrera, Mari-Carmen et. al. (2008) Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. Retrieved from

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Heather is a holistic health educator, herbalist, DIYer, Lyme and mold warrior. Since founding in 2009, Heather has been taking complicated health research and making it easy to understand. She shares tested natural recipes and herbal remedies with millions of naturally minded mamas around the world. 

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73 thoughts on “Synthetic Vs. Natural Vitamins: Why It Matters & How to Tell the Difference”

  1. Great post! I went though different phases of supplementing with my kids. As I went along, I landed on probiotics being a major player in keeping my kids healthy (based on experience not science at that time). I do however still believe in outside supplementation with some of the ‘real food’ supplements. This can especially be the case when you are dealing with lots of food allergies and thus many food restrictions. In my case, I am severely allergic to casein (all forms), ghee is not an option either (especially homemade) since there are trace amounts of casein in it…even in the brands that say ‘casein free’. I do yearly blood tests to see how my levels are, this helps me not blindly supplement. I encourage people to work with a natural Doc they trust to help them decide what to, or what not to supplement with. Both options can be a shot in the dark. If there are obvious health issues in a persons family I think informed supplementation can be a life saver…but YES, never a replacement for good healthy nutrient dense eating!

    • That’s very interesting, Raquel! I am not against supplements at all, but as you know from experience it takes a lot care and consideration to keep things balanced!

    • Interesting thoughts, Jenni! During parts of my pregnancy it was extremely rainy and I did not get enough Vitamin D, so that could have played a role in the cal/mag imbalance. I did not know about supplementing with D3 at the time . . . all I knew what that I was craving sunlight like crazy. Anyway, you’ve given me food for thought. Thank you!

      • I would like to know how a company can sell a product with something like retinol which is animal-based or vitamin K2 MK4 which also only comes from animal products, and state that their products are vegan. To me, this is a contradiction in terms. How is it possible to have vitamins that can only be derived from animal products and label them as being vegan? I am not vegan but I get suspicious of these supplements that claim to be vegan even though the vitamins included can only be sourced from animal products. I would greatly appreciate your Insight on this matter.

  2. That’s interesting, Joanna! I think my response to that would be to say that it’s not that we don’t see some benefits from synthetics, but that if they are taken consistently we could end up experiencing unintended consequences that cancel the benefits. For example, I got relief when I took megadoses of magnesium but then had to help Katie remineralize her teeth because she didn’t get enough calcium in utero. Make sense?

  3. Hi Keller! I took prenatals with my first but not my second. Personally, if a mom is just getting started with real food while pregnant I would probably recommend a whole food supplement. I can’t comment specifically on Juice Plus because I haven’t looked at their label, but they’re not one of the few companies I’ve been able to verify that is doing things top notch.

  4. Hi A.B. – I have taken Garden of Life before and thought they were pretty good . . . but that was before I knew what to look for! Honestly it’s been a long time since I looked at their info so I can’t really say. Sorry I can’t be more help on this.

  5. You may want to check the ingredients of the Poly-Vi-Sol. I think you’ll find they’re exactly what she’s talking about here.

    • My doctor told me also to use polyvisol and i know that it is terrible. I have been searching for a better option. Any suggestions.

  6. I agree that you have to be really careful about what you supplement with. Unfortunately much of our food supply’s nutritional value is dwindling, meaning that even if we eat a wide variety of healthy foods and rarely waste our “nutritional space” on empty foods we still may be deficient. Especially if our guts and/or digestion are compromised. I’m not sure what the correct answer is. I do know that when my N.D. recommended that I take IntraMax I could feel a dramatic difference in my energy levels. I’ve since stopped taking it for a few years and have to admit that I feel pretty bad and am desperate for something to bring my energy levels back up (trying The Mood Cure) My gut health is definitely not what it should be, and I just don’t think I can get everything I need from my bone broths, herbal infusions, FCLO/butter oil, and general eating (I have to confess there’s been a lot of chocolate in there, too). But what to do?

    • Yep, due to a lot of factors there are some likely areas of deficiency even when we’re eating well. I’ll cover those in the next post and share how I try to fill in those gaps.

    • Big Health Supplements Industry (the even nastier twin of Big Pharma) wants everyone to think that health salvation can be found in a supplement. Let’s all stop being stupid and promise we will never buy a supplement again !

    • Please check out “forks over knives”. Butter will never be better then veggies… absolutely ridiculous and honestly not good advice.

      • “Forks Over Knives,” is a particular Vegan point of view. Its recommendations and those of its supporters ignore a body of research not in keeping with its orthodoxy. there is research that shows there are genetic populations, primarily among Asians, that are more amenable to this type of diet. For an excellent research and clinical practice based resource on dietary types, I suggest you read, “Nutrition and the Autonomic Nervous System,” by Nicholas J. Gonzalez, MD. Both the more extreme forms of Vegan and Paleo are outlier diets suitable for a small percentage of the population. Different diets are suitable for different people according to their sympathetic or parasympathetic dominance. Researching best dietary approaches is a long road, and much research continues to issue forth–some excellent, some biased, and some industry financed bogus examples of fraudulent or misleading poor quality. I applaud the continued efforts of this blogger to endeavor to learn more. Thank you for your suggestion about butter; respectfully, different fats for different folks.

      • Forks over Knives is just scare tactic propaganda. I’ve never seen a healthy looking vegan. We need small amounts of meat in our diets and tons of veggies.

  7. I’m loving the comments, too! 🙂 And hey, we do NFP! Quick question for you: how are you testing yourself? I do muscle testing with my herbalist but I can’t do it for myself. That would be super-helpful!

    • If I need muscle testing done I usually bring my husband along and he’ll help test me. I will also use the pendulum method if he can’t come but I make sure to double check everything with my husband testing me later. I’ve never had an instance where the results didn’t line up, though, so it has been pretty reliable for me. Hope that helps! And YEA!! for NFP! 😉

  8. I’ll do my best to go over those in the follow-up, Grace! If I forget just leave me a message and I’ll add it in. And you’re right, sometimes food isn’t enough. Wishing you health and healing in the New Year!

  9. Not sure. Just in case I forget I’ll say this. I think their ingredients are high-quality but they use the binders I was talking about that decrease absorption. That’s my take for whatever it’s worth . . .

  10. Hi Robin! I’m so glad this was helpful. A magnesium and possibly other mineral deficiency sounds like a good guess. I’ve been wanting to read that post by Cheeseslave but haven’t had a chance yet. Is it just magnesium or is it a multi-mineral? I may be wrong on this but I think the ratio of calcium to magnesium supplementation is supposed to be 2:1, so you might want to add in a calcium supplement. But maybe that is counter-productive? Ack! It’s easy to out think oneself here – that’s why I like food! Personally, I take epsom salt baths or spray magnesium oil on my skin to make sure I get enough. It is my understanding that the skin will absorb only what it needs so you don’t have to worry about overdosing.

    • I think sometimes you need a little more magnesium than the normal 2:1 ratio, in part because magnesium is utilized by so many other vitamins/minerals, in addition to calcium. I know that a magnesium and sometimes cal/mag supplement helps with my restless legs. I also read in The Mood Cure that it may be linked to deficiencies in folate (I hate calling it folic acid, like that’s the natural form), iron, or vitamin E. I try to drink nettles and/or red raspberry leaf infusions daily because they are high in mag/cal and other minerals but missing just a few days, or a few days of eating poorly can make it hard to recover without a little supplemental boost.

  11. Heather, I am so glad you wrote about this!

    I’ve been skeptical of vitamins for a long time, but now there is actually scientific evidence that is backing my theory.

    I know of at lease five people that took water soluble vitamins in high doses for years. Two got kidney cancer and died and the other three have failing kidneys. They all believed it was their vitamins causing their kidney issues. My last friend who found out her kidney function was way off stopped taking her vitamins immediately and her function returned to normal. That is scary…especially since water soluble vitamins are supposed to be “safe”

    With that being said I will randomly pop a vitamin B or prenatal pill….I really need to up my greens and just stop….

  12. I think Ramiel Nagel may touch on that in his book, Curing Tooth Decay, but I’m not 100% sure. Maybe you could search his website (www.curetoothdecay) and see if anything pops up . . .

    • I would be interested to know what you found out about melaleuca! The company as q whole does not seem very honest, as they tout “all natural” cleaners that are NOT all natural.

      • I’m a Melaleuca customer. The company actually says their cleaners are non-toxic and are powered by natural ingredients such as lemon, thyme, etc. They don’t claim organic nor 100% all natural ingredients. They do use enzymes to increase the efficacy of their products. It may be a term some customers naturally use to describe the products just because of the natural ingredients in them. However, “All natural” even when used with food labels is hardly all natural because the term is not regulated as the term “organic” is regulated. Hope that helps 🙂

    • My daughter takes the MegaFood Kids One Daily and also Dr. Christopher’s Original Formulas Kid-e-Mins. I’d like to change things up and see what else is out there but a lot of kids vitamins have sugar, ugh. Also, synthetic ingredients. I saw your post about kids vitamins and that you were going to post something about what you give your kids has that been issued yet?

  13. heather! thank you AGAIN for such a well thought out article! i “knew” some of this, but, probably like many, did not know the depth of it.

  14. Hi Meg! I think juicing is a great idea. Here’s a follow-up to this post in which I talk about it:

    I haven’t looked into Juice Plus, but I like Dr. Ron’s Ultra Pure. Most capsules are made of gelatin, which often comes from conventional cows. Dr. Ron’s capsules are made from non-GMO sources . . . in my opinion that represents the amount of care they’ve put into creating their products.

    • Anything that is grown has a good chance of having lead or other heavy metals (minerals) in it. This is because the soil has them in it. Did you know that apple juice has arsenic? Chocolate bars tend to have more lead than most supplements (more that is regulated by Prop 65) but the industry tends to ignore that because it is food not a supplement. There is also a big difference between organic and inorganic minerals. Organic arsenic is not as toxic as inorganic arsenic.

  15. I know this comment’s years old now, but for you or anybody else, I found super helpful, useful and effective after days of research on the topic. They have a free ‘course’ explaining everything and their charting tools are what are really helpful afterwards. You can input data on the computer or via their app on your phone, I eventually opted for the paid VIP membership for extra charting details/options, but it would work just as well with the free version.

  16. We’ve tried them, but we like to use whole food vitamins (not synthetic) and we switch between Hakuna Matata vitamins and Standard Process.

  17. The vitamins are all synthetic with a proprietary blend of whole foods based powders mixed in. It is better than most synthetic vitamin brands as far as additives and fillers, but it is still synthetic.

  18. My husband is not a veggie eater but recently had some bloodwork indicating he needs to eat healthier. He has started buying all kind of veggies in bulk and dehydrating them, then powdering them and putting them into capsules, for vitamin d he dehydrates portabello mushrooms. He has also alterd his diet and uses some of the powdered veggies in his egg whites soups, stews and eats no red meat but mainly fish, chicken and beans. He’s lost 26 pounds and has more energy. I have also been taking many of the homemade supplements he makes. We are in our mid sixties and feel better than we have in years.

  19. Superkids Liquid Multivitamins contains B-12 as Cyanocobalamin. I have read multiple articles that state many multivitamin manufacturers use this synthetic form of B-12 because it is cheaper to make and has a longer shelf-life (as compared to Cobamamide, Methylcobalamin or Adenosylcobalamin). This form of B-12 cannot be readily absorbed and contains trace amounts of cyanide, making it slightly toxic if taken over an extended period of time.

  20. Hi, not sure if this will help but most of the laundry detergents and softers contain furmeldahide to make them last longer which is known to cause ear infections. Our skin is our largest organ and just absorbs these cemicals. Maybe try organic cleaners and lotions. Best wishes 🙂

  21. I am looking for information on these as well (specifically the baby & toddler powder.) They are currently out of stock anyway, but my concern is the folic acid…. I’d love to find a whole food multi supplement. Anyone have any other suggestions?

  22. I just received an answer from MegaFood on my question:
    “Please let me know what is the ‘Vegetable Lubricant’ which is one of the ingredients of the ‘Magnesium 90 Tablets’.
    What is that lubricant made of and what is its content in percent in each tablet.”
    “The Vegetable Lubricant is Stearic Acid. MegaFood is a magnesium stearate-free company. It is a vegetarian/vegan fatty acid derived from palm fruit used sparingly as needed to prevent the foods/botanicals in our formulas from sticking to our tablet presses – – much the same as the way in which wax paper or an oil coating is used to prevent cookies from sticking to a pan when home baking.” signed by Michelle Miller | Customer Experience Representative
    So that was clear to avoid their products.

  23. Hi Keller,

    Could you please give me the names of the companies of the probiotics and cod liver
    that your son is taking?

    Thank you.

  24. Hi Ellen,

    Could you please tell me the name of the product and the company you take
    the liquid plant derived minerals?

    Thank you.

  25. I have just figured out that I am very sensitive to cellulose/Avicel which is used as a filler in meds, supplements, OTC & foods. It is made from pine bark & humans cannot digest it, although beavers can. I’m NOT being funny, Even though many may not have any reaction, I feel that it builds up in our bodies & it probably causes inflammation. Please research this! Thank you.

  26. Great post! I just used some of what I learned from you in choosing our kid’s vitamins.

    I used to give them SmartyPants, then found out some really bad things about the product. Our pediatrician suggested switched to Hiya vitamins ( and so far we LOVE Hiya and what they stand for.

    Thanks for your article!

  27. Hi I’m wondering what b-complex supplement you use? I’m having a hard time finding one that is not synthetic. Thanks!