The Top Foundational Supplements Everyone Should Be Taking and Why

Top Foundational Supplements

I have a love-hate relationship with the internet. On one hand, it’s a fantastic way to get great information right at your fingertips (like this article!) On the other hand, it is full of conflicting information – especially about health, and even more specifically about vitamins and supplements. If the internet is your source for information about what supplements you should and should not take, it can get pretty confusing and many of my patients tell me they don’t know where to start. Part of the problem is that there are thousands of supplements on the market – probably hundreds of thousands, maybe even millions.

As a functional medicine practitioner, I have my informed opinions about the wide range of well-intentioned supplements that I consider to be unnecessary. Oftentimes, any individual really only needs a small handful of targeted vitamins and supplements that will actually be beneficial. Let’s cut through the confusion to determine what supplements you should take, and how to incorporate them into your existing routine.

Essential Supplements - What Supplements You Should Take

Out of the seemingly endless vitamins and micronutrients, these are the handful I think are the most essential to your wellness routine as they help lay a solid foundation for your overall health.

1. Vitamin D

No other vitamin can hold a candle to vitamin D when it comes to importance and influence on health. Since vitamin D is fat-soluble, it acts more like a hormone than a vitamin by regulating hundreds of super important pathways in your body. Besides your thyroid hormones, this vitamin is the only other thing every single cell of your body needs in order to function properly. Also known as the sunshine vitamin, vitamin D is synthesized by your body when your bare skin is exposed to sunlight. It is impossible to get enough vitamin D from food alone, and unless you live in a very sunny place (like near the equator) and are outside frequently without sunscreen, you are probably deficient. This is therefore one of the most important supplements you should take.

Dosage: If you have had your vitamin D tested by your doctor, you will find that the standard reference range for vitamin D levels falls between 50 and 60 ng/mL. In functional medicine, we aim for an optimal range between 60 and 80 ng/mL. Depending on where your starting levels are, you should be taking anywhere between 2,000 and 6,000 IU of vitamin D per day. Make sure to test your vitamin D levels to find out your starting point, and retest to gauge how your vitamin D level optimization is going. This is a common and easy test and your doctor will likely be fine with it if you ask.

How to incorporate: Since vitamin D is fat-soluble, take advantage of vitamin synergy by combining your supplement with other fat-soluble vitamins, such as A and K2. This will help make it more bioavailable and balanced. It’s also a great idea to take them with fatty foods like avocado, olive oil, wild-caught fish, and coconut to increase their bioavailability. If you put fats in your daily smoothie (and you should!), this is a good time to pop that vitamin D as well.

2. Magnesium

Magnesium is a crucial mineral needed for over 300 essential biochemical reactions in your body, including the regulation of neurotransmitters. Up to 80 percent of the population is deficient in this nutrient, and that deficiency can show up as problems with sleep, anxiety, migraines, and brain fog. Most deficiencies come from a poor diet or gut problems that interfere with magnesium absorption.

There are many different forms of magnesium, so let’s break down the best. Magnesium oxide is the most commonly found in supplement form, but it is not nearly as easily absorbed as other forms. Magnesium citrate is a good option, especially if you tend to get constipated. Magnesium glycinate is excellent for its calming effects, and magnesium threonate has shown promise for its neurological support. Magnesium oil is another great way to boost this vital nutrient. You rub it on your skin instead of ingesting it.

Dosage: 350 mg per day.

How to incorporate: Taking magnesium right before bed is often best as it promotes better sleep by relaxing muscles and helping boost levels of the calming neurotransmitter, GABA, in your brain.

For more information on magnesium as a supplement, read this article.

3. Probiotics

As Hippocrates said, “All disease begins in the gut.” Science is finally catching up, with research showing that the gut is the foundation for almost all aspects of your health – regardless of whether you are having digestive symptoms or not. Your gut microbiome contains trillions of bacteria, many of which are beneficial to human health, and some which can cause health problems. When the bad guys start to outnumber the good guys, it can affect everything from your weight to your hormones. While it is important to include probiotic-rich foods into your diet (give kefir, sauerkraut, kimchi, and kombucha a try). If you struggle with permeability in your gut, a probiotic supplement may be the best supplement to take.

Dosage: At least 10 billion CFU per day.

How to incorporate: Feed the probiotics you are trying to grow with prebiotic foods rich in fiber, especially garlic, asparagus, and onions. These foods help facilitate the growth of good gut bacteria. When choosing a probiotic, make sure to take on that includes strains of Lactobacillus and Bifidobacterium. These two specific strains have been shown (1) to reduce inflammation. I am also a fan of soil-based probiotics (SBO) to further support rich bacterial diversity.

For more information on choosing the right probiotic supplement for you, check out my article here.

4. Omega-3s

Your brain itself is about 60 percent fat, so depriving your body of fat can contribute to all kinds of unpleasant brain symptoms, from brain fog and fatigue to depression and anxiety. In other words, healthy fat is essential for optimal brain health. If you’re not getting enough healthy fats, specifically from wild-caught seafood, you might want to consider an omega-3 fish oil supplement. Omega fats can be found in plant sources such as flax, but it’s not easily used by our bodies because it must be converted into DHA or EPA, which is an inefficient process. Because of this, I suggest getting your omega fats from krill oil, or fish oil from salmon, cod liver, or sardines. This is a supplement you should take if fish isn’t a part of your regular diet.

Dosage: 2250 mg EPA / 750 mg DHA per day.

How to incorporate: If you’re eating more omega-6 fatty acids (like those found in many types of vegetable oils, you may be suffering from increased inflammation. Fish oil may noticeably reduce these inflammatory effects.

5. Spirulina

Think of this blue-green algae as your superfood of the sea. Spirulina is a great source of iron, phytonutrients, and iodine, all commonly lacking in the modern Western diet.

Dosage: 3 grams per day.

How to incorporate: Spirulina is most commonly available in powder form, which makes it perfect to just stir into your tea or add to your daily smoothie! I love spirulina so much that I added it to my co-branded supplement with Agent Nateur, holi ( y o u t h ). This powdered supplement is great added to a glass of cold water with lemon.

6. Turmeric

Inflammation is at the center of every chronic health problem today and turmeric is a spice that contains one of the most powerful natural anti-inflammatory tools we know of. Whether you use the spice itself, or its active component (curcumin) in supplement form, this is a supplement you should take if you are on the anti-inflammatory war path.

Dosage: For those looking for inflammation maintenance, 2 grams per day is a good start, but as much as 10 grams per day may be needed (2) to drive down higher levels of inflammation.

How to incorporate: Unless you know you have a problem with inflammation, don’t worry about using turmeric every single day. For most people, using turmeric in cooking a few times a week is enough to enjoy the benefits. Always add black pepper, which contains piperine, because it increases the bioavailability of curcumin by 2,000 percent. If you are struggling with chronic inflammation, take a turmeric supplement every day, and find a supplement that also includes piperine.

Shop This Article

Dr. Will Cole's Personal Picks

To Elevate Your Wellness

7. Vitamin C

This immune-boosting, common-cold-busting vitamin can reduce (3) symptoms of the cold by up to 30 percent. Most people get enough from food (65 to 90 mg per day), since a lot of foods contain it. Don’t worry about this supplement unless you feel the sniffles coming on.

Dosage: 1,000 to 4,000 mg per day to boost your immune system and promote healthy skin.

How to incorporate: Combining with zinc can increase vitamin C’s immune-boosting properties. Look for powdered supplements that you can mix with water to take with you for when you start to feel a little less than 100 percent.

8. Zinc

Your body has no way to store this important mineral, so it is important to make sure you’re getting this through your diet or supplementation. Zinc’s main role is to help your body increase white blood cells and fight off infection, and it also assists with the release of antibodies. Deficiency has been linked (4) to increased instances of sickness, so it is no wonder you often find zinc as a common ingredient in the cold and flu aisle of your pharmacy. As I mentioned above, supplements that combine the power of vitamin C and zinc are the best supplements to take.

Dosage: 15 to 30 mg per day. Pregnant women should aim for 12 mg per day since its essential (5) for normal fetal development.

How to incorporate: If you’re eating a healthy well-rounded diet, you should be getting in the proper amount of zinc per day without needing a supplement. But if getting over a cold quickly is your goal, supplementing at least 75 mg per day can reduce (6) cold duration and symptoms so you can get back to your life.

9. Methylated B Complex

B vitamins are the fuel behind methylation, a biochemical process that happens more than 1 billion times every single second inside your body. It helps keep you alive and healthy by assisting your body’s ability to properly detox. There are so many different types of B vitamins, so it’s important to get a well-rounded amount of each.

Dosage: 400 to 800 mcg methylfolate (B9), 1,000 mcg methylcobalamin (B12) per day.

How to incorporate: The best B-vitamin supplement would be a B-complex vitamin containing methylated B vitamins, especially if you have methylation impairments like the MTHFR gene mutation. Look for activated B vitamins like B9 L-Methylfolate (L-5-MTHF), B6 Pyridoxyl-5-Phosphate (P5P), and B12 versions (such as Adenosyl B12, Cyano B12, Hydroxycobalamin B12, or Methyl 12).

10. Vitamin A

Vitamin A is essential for a strong immune system and vitamin A deficiency has been linked (7) to autoimmune diseases, which are on the rise in a major way. Some researchers believe this has to do with our dendritic cells; our alarm cells of the immune system that can send out a “red alert” to stimulate immunity, or a “calm down” message that tones down excessive immune reactions that can damage the body. The “calm down” message makes use of vitamin A.

Plant beta-carotenes, a precursor to vitamin A, are found in sweet potatoes and carrots but the conversion rate to the usable retinol is very weak. In fact, research suggests (8) that just 3 percent of beta-carotene gets converted in a healthy adult. Because of this, look for vitamin A sources from either whole-food sources like fish liver oil or retinyl palmitate.

Dosage: 2,000 to 10,000 IU per day.

11. Vitamin K2

Vitamin K2 is one of the most common nutrient deficiencies in the Western diet, but it is essential for controlling inflammation. One study (9) in the Journal of Neuroimmunology found that vitamin K2 was effective at inhibiting the pro-inflammatory iNOS in the spinal cord and the brain immune system in rats that had multiple sclerosis symptoms. There are several types of K2, but I suggest looking for the MK-4 version. MK-4 regulates gene expression in specific ways that no other form of vitamin K does. MK-4 plays an exclusive role in cancer protection and sexual health.

Dosage: 100 to 200 mcg per day.

How to incorporate: Taking these fat-soluble vitamins together with vitamin D will help keep your levels from going too high as well as making vitamin D more bioavailable to your body! Take them with a fat-containing meal such as avocado, salmon, or just a bit of butter or coconut oil added to whatever you’re cooking.

12. Collagen

This protein helps form our connective tissue, including tendons, skin, cartilage, bones, blood vessels, ligaments, and more. It also helps regulate metabolism and our body’s own collagen production. Made up of three amino acids (glycine, proline, and hyroxyproline), each produced in our body but not at sufficient levels, most people can benefit from a collagen supplement. For example, we require around 15 grams of glycine per day, but most of us only get 3 grams per day from our modern diet.

Dosage: 8 grams per day.

How to incorporate: Powdered collagen peptides are fantastic because these are easy to add to smoothies or any other liquid, making them one of the best supplements to take. Look for brands that derive their collagen from grass-fed and pasture-raised protein sources or use marine collagen, for the purest, toxin-free form. My co-branded supplement with Agent Nateur, holi ( m a n e ) is formulated with marine collagen for maximum bioavailability.

13. Antioxidants

Considered the “building blocks of life”, your cells make up every single organ in your body and ensure all systems of your body function properly to keep you healthy and thriving. Antioxidants are compounds that support vibrant cellular health by fighting against free radical damage produced by oxidative stress from outside triggers that we face on a daily basis like toxins, poor diet, and stress. Certain vitamins like A, C, and E are considered antioxidants as well as zinc, so if you are taking a supplement antioxidant compounds are commonly found in fruits like pomegranates, grapes, and berries, we don’t always eat enough of these on a daily basis - especially if you are exposed to more of these oxidative triggers in your job - making supplementation a vitamin part of your wellness puzzle. 

Dosage: Certain vitamins like A, C, and E are considered antioxidants as well as zinc, so if you are taking one of these in supplement form and eating a wide range of antioxidant-rich foods, chances are you don’t necessarily need to supplement with a set antioxidant supplement. However, if you are exposed to an onslaught of oxidative triggers in your job a daily targeted supplement can be beneficial.

How to incorporate: You can find supplements formulated with targeted antioxidant compounds like my supplement The Antioxidant, with compounds from these antioxidant-rich foods like pomegranates, grapes, and more.

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe.

READ NEXT: Exactly How To Determine The Quality Of Your Vitamins + Supplements

View More At Our Store

Purchase personally curated supplements
and Dr. Will Cole’s books!

Bew Global Shop Banner
  1. Rodes, Laetitia et al. “Effect of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharides and inflammatory cytokines: an in vitro study using a human colonic microbiota model.” Journal of microbiology and biotechnology vol. 23,4 (2013): 518-26. doi:10.4014/jmb.1205.05018
  2. Aggarwal, Bharat B et al. “Anticancer potential of curcumin: preclinical and clinical studies.” Anticancer research vol. 23,1A (2003): 363-98.
  3. Anderson, T W et al. “Vitamin C and the common cold: a double-blind trial.” Canadian Medical Association journal vol. 107,6 (1972): 503-8.
  4. Keen, C L, and M E Gershwin. “Zinc deficiency and immune function.” Annual review of nutrition vol. 10 (1990): 415-31. doi:10.1146/
  5. Simmer, K, and R P Thompson. “Zinc in the fetus and newborn.” Acta paediatrica Scandinavica. Supplement vol. 319 (1985): 158-63. doi:10.1111/j.1651-2227.1985.tb10126.x
  6. Singh, Meenu, and Rashmi R Das. “Zinc for the common cold.” The Cochrane database of systematic reviews ,6 CD001364. 18 Jun. 2013, doi:10.1002/14651858.CD001364.pub4
  7. Ikeda, Utako et al. “1α,25-Dihydroxyvitamin D3 and all-trans retinoic acid synergistically inhibit the differentiation and expansion of Th17 cells.” Immunology letters vol. 134,1 (2010): 7-16. doi:10.1016/j.imlet.2010.07.002
  8. Hedrén, E et al. “Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method.” European journal of clinical nutrition vol. 56,5 (2002): 425-30. doi:10.1038/sj.ejcn.1601329
  9. Moriya, Masayuki et al. “Vitamin K2 ameliorates experimental autoimmune encephalomyelitis in Lewis rats.” Journal of neuroimmunology vol. 170,1-2 (2005): 11-20. doi:10.1016/j.jneuroim.2005.08.001

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.

Our content may include products that have been independently chosen and recommended by Dr. Will Cole and our editors. If you purchase something mentioned in this article, we may earn a small commission.



Evidence-based reviewed article

Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is also the host of the popular The Art of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, Gut Feelings, and The Inflammation Spectrum.

Gut Feelings Dr. Will Cole 6

Gut Feelings

Healing The Shame-Fueled Relationship
Between What You Eat And How You Feel