When should I supplement?

When should I supplement?

Margie GanderJul 9, '19

A stroll down the vitamin aisle at your local pharmacy can be overwhelming and expensive. It is also difficult to determine which supplement you should be taking and why. You may even doubt whether you are absorbing the ingredients or as one client said to me; taking supplements results in having a very expensive wee!

It is true, vitamins and supplements are BIG business. The vitamins and supplement market in SA has increased from R 2.9 billion in 2014 to R 3.8 billion in 2016, and is growing at a healthy rate of 13.5% per annum; with about 46% of South Africans buying supplements monthly. I think it's great that so many of us want to be healthier and are invested in buying supplements BUT what concerns me is how many of us are taking the right supplements for our unique genotype and biochemistry, in the right dosage and at the right time of day? 

Nutrigenomics has empowered us to personalise most of our health choices, specifically when it comes to diet and supplementation. A "one size fits all" approach to nutrition is no longer true when you know what your unique genetic variations are and what nutrient co-factors are required to support these pathways for optimisation. 

When it comes to supplementation, it's important to start by asking the following questions:

  1. Am I deficient in this nutrient? What does my genotype indicate and what is my biochemistry showing. 
  2. Is the product produced according to Good Manufacturing Practice?
  3. Are the active ingredients in their bioavailable form?
  4. What are the inactive ingredients? Avoid chemical preservatives and additives, fillers, binders, GMO, sugars, and gluten.
  5. What dose should I take?
  6. When is the best time to take the supplement? 

Food first

You can't supplement yourself out of a bad diet! In my Functional Medicine Coaching Practice, we always try to start with an Institute of Functional Medicine diet plan. Ideally, we chose the plan best suited to your genotype and/or biochemistry. If a client hasn't done any DNA or biochemistry testing, we then work with a 'what' the client is currently eating and see how we can modify it according to their health goals. These diet plans have been compiled using therapeutic foods for specific needs; such as detox, cardiometabolic support, thyroid support, and mitochondrial support. I just love the idea of therapeutic foods as it empowers you to view your food choices not in terms of calories but rather in terms of support for your genotype and biochemistry. 

What is really important when personalising your diet choices, is to understand the best macronutrient distribution for you to maintain a healthy weight and well being. Macronutrients such as carbohydrates, proteins, and fats are easy for your body to absorb. You absorb an estimated 90% of the nutrients available from macronutrients. Cooking food, chewing it, digestive enzymes and the overall digestion process all help make macronutrients bioavailable to the body.

When it comes to micronutrients such as vitamins and minerals, flavonoids or carotenoids, it’s a different story. These exist in a different form in food that makes how you absorb and utilise them not so predictable due to your unique genotype and biochemistry. It is because of this, that many of us 'add in' supplements to ensure that we are getting enough of these important nutrients. The problem comes in when your supplementation is not what YOU need, it not bioavailable or not in the correct dosage. 

Sometimes food is not enough. This could be due to your unique genotype coupled with your current lifestyle choices. Crash diets, poor sleep, insufficient and/or imbalanced nutrition, demanding periods such as extensive exercise or emotional and/or physiological stress can put you at an increased risk for inadequate micronutrient status. 

Why is bioavailability important?

If a supplement is not bioavailable, then the supplement ingredients are not absorbable and can't be delivered in their proper form to the target site in the body, then they can't do their job. When it comes to taking vitamins, you can pop all the pills you want, but if the ingredients aren’t bioavailable to your body, then you’re wasting both time and money. With some large molecules that are difficult to absorb, like CoQ10 and curcumin, bioavailability really matters. 

Other absorption considerations include whether nutrients are fat-soluble (vitamins A, D, E or K) or water-soluble, which are easily excreted (vitamins B and C). Carotenoids, for instance, are fat-soluble. Ingesting carotenoids with fats or oils makes them more bioavailable to the body.

Many vitamin tablets and pills also contain extra fillers, binders, and artificial ingredients. These ingredients make it harder for the body to access the nutrients and therefore it is really important to read the ingredients label before purchasing. 

Signs of a micronutrient deficiency

It's important to know when you are deficient in a certain micronutrient. I believe that micronutrient deficiency is one of the precursors to chronic diseases such as osteoporosis, type 2 diabetes, Alzheimer's disease, obesity and certain cancers.  

The table below shows how micronutrient deficiency can send you done a path towards chronic disease:

Action  Evidence  Symptoms
Stage 1: Depletion of vitamin and mineral stores due to stress, diet, or illness Measurement of vitamin/mineral levels in blood and tissues Low-energy and tiredness
Stage 2: Biochemical adaptions
Decreased excretion of metabolites in the urine
Low-energy and tiredness
Stage 3: Secretion of micronutrient dependent enzymes are reduced
First physical signs; lack of energy, malaise, mood changes, loss of appetite, and insomnia


Oxidative Stress

Detoxification problems

Poor methylation


Stage 4: Reversible impairment of metabolic pathways and cellular function
Morphological, metabolic or functional disturbances. More pronounced physiological changes
Problems with immune function
Stage 5: Irreversible tissue damage
Clinical signs of micronutrient deficiency
Chronic diseases


Critical co-factors based on your genotype

A cofactor is a non-protein chemical compound that is required for an enzyme's activity as a catalyst, a substance that increases the rate of a chemical reaction. In diet and supplementation, you should be consuming important nutrients that provide the co-factors to the enzymes encoded by your unique genetic pathways. This is called nutrigenomics. Cofactors can be considered "helper molecules" that assist in important biochemical transformations; deep in your biochemistry and are critical for optimal health. 

I find this table really helpful in determining which nutrients co-factors support certain important genes. This list contains only a snapshot of some of the more commonly supplemented nutrients, as the list is endless! 

Gene Function  Nutrient co-factor  Test 

If you have the GG allele in this gene, you are likely to have a severely reduced ability to transport vitamin B12 into your blood cells. If you experience any of the symptoms listed or suspect low vitamin B12 levels (e.g. if you follow a vegetarian or vegan diet or consume a large amount of alcohol), have your vitamin B12 levels tested, increase your intake of vitamin B12 foods and/or supplements and minimise alcohol intake. Vitamin B12 is also important for healthy methylation.



Whole Exome 

The A-allele is associated with mood, osteoporosis, certain cancers, and diabetes. If you carry this allele then it is important to note that your risk can be exacerbated by a caffeine intake > 300 mg/d. It is important for you to eat foods rich in vitamin D as well as test your vitamin D levels regularly. In Functional Medicine, the optimal level is considered to be 70. 
Vitamin D3 


Whole Exome

If you carry the TT-genotype in this gene then it is recommended that you do not smoke, avoid polycyclic aromatic hydrocarbons (PAHs) found in smoked foods and chargrilled meats. Increase intake of cruciferous vegetables and add in a supplement with sulforaphane (a compound found in broccoli).  


Whole Exome

GPX1 encodes a member of the glutathione peroxidase family, which contains important antioxidant enzymes and helps detoxify hydrogen peroxide with glutathione, and thereby protect cells against oxidative damage. It protects the hemoglobin in red blood cells from oxidative breakdown.




Whole Exome


To get started on your personalised supplement journey, book a Functional Medicine Coaching session:




I like to supplement my diet. What I like, even more, is knowing that what I am supplementing with, is providing my body with the nutrients that it needs the most. No more guesswork, but rather better choices based on my own scientific data. 



Written by:
Marguerite Doig-Gander
BA (Speech, Hearing & Lang Therapy) Hons | FMCHC | ReCODE Coach 

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