How to Pick the Right Vitamin
As a naturopathic doctor, I frequently get asked about which multivitamin is best. But the truth is, I’m just not that into multivitamins. Why? Because a one-size-fits-all approach to health is not the naturopathic style and that’s precisely what multivitamins are. More often than not, they don’t have enough of any vitamin or nutrient to be useful for clinical indication.
Many multivitamins are full of fillers and are quite expensive. On top of that, many of their nutrients are excreted in the urine rather than absorbed. The only exception I would make for the use of multivitamins is for malnourished patients or perhaps geriatric patients who are not getting adequate nutrition. Even the standard North American Diet provides enough basic nutrition, rendering a multivitamin virtually useless.
However, this doesn’t mean that I’m completely opposed to vitamin or nutrient supplementation. Many patients’ diets will have areas for improvement and can certainly be lacking in some vitamins or nutrients. However, identifying key patient deficiencies must be accomplished through accurate diet diaries, routine blood work, patient demographics and thorough intake of a patient’s presenting symptoms as well as physical examination. This is why a regulated healthcare professional with knowledge of both nutrition and pathophysiology should be consulted before choosing any supplement. Enter a naturopathic doctor.
Many medical doctors write off supplementation due to poor absorption and they make a fair point. A tiny tablet or capsule containing a concentrated amount of nutrient has little surface area to get absorbed. On top of that, their transit through the digestive tract can be quick, further reducing the chance for absorption. But there are a few ways to maximize absorption.
First off, spreading out doses is crucial. Over one gram of vitamin C can cause diarrhea in patients because water is drawn into the intestine by osmosis 1. Not only is this a waste of vitamin C, but it’s also causing an unpleasant symptom for the patient. If your regulated healthcare provider advises you to take high doses of vitamin C (for immune boost, or dietary deficiencies) make sure you spread the dose out over the course of the day 1. Buying lower dose supplements allows for this control.
Taking supplements with a meal is another great way to boost absorption. The presence of food will slow the transit time of the supplement thereby allowing more time for absorption 2. Some vitamins are completely fat-soluble (namely A, D, E and K) so they should always be taken with a fatty meal. Of course, some supplements—like iron—should not be taken with food and the regulated healthcare provider should advise this.
Many vitamins and nutrients are best absorbed together rather than solo. This should come as no surprise since we’re really supposed to get our nutrition from food, which almost never has just one or two constituents in it. One example of this is iron supplementation and vitamin C. Studies show that supplementing iron with vitamin C can prevent the associated unpleasant gastrointestinal symptoms 3. It is common for naturopathic doctors to advise patients to take various supplements with foods that are high in certain nutrients for optimal absorption.
The body’s tissues best absorb some supplements when alkalinity of the blood is normal. Calcium is a good example of this. Naturopathic doctors frequently test urine alkalinity prior to prescribing calcium supplements in patients at risk of developing osteoporosis. The standard North American Diet is high in meat and low in vegetables. This frequently leads to slightly acidic blood 4. Alkalinizing the blood by increasing vegetable consumption (or in some cases with bicarbonate supplements) can prep the body for adequate calcium supplementation. A regulated healthcare provider should monitor this process.
Another aspect of supplement absorption is the form the supplement takes. Just like pharmaceutical drugs, supplements come in different salt forms. Salts are attached for stability purposes and do not usually play a role as active ingredients. By now we know that calcium citrate is far better absorbed than calcium carbonate so it is almost exclusively preferred today 5. Some supplement forms can be recommended based on the clinical indication. Magnesium is a great example of this principle. Magnesium sulfate is not the best absorbed form but this actually makes it the preferred form for constipation because it remains in the intestine and draws water in 6. Magnesium taurate on the other hand, is more indicated for cardiac conditions because of its dilating effects on blood vessels 7.
The last piece of advise on supplementation is to buy high-quality professional brands. Health Canada is not as stringent on natural health products as they are on drugs so there are many more brands on the market that employ different manufacturing practices. Supplements are recalled every day by Health Canada due to poor quality and safety concerns. Consult a naturopathic doctor before choosing a product because we have knowledge on which brands practice high quality control and batch-to-batch consistency. Professional brands have appropriate potencies as well so you’re getting what you pay for. These may be more expensive but it’s ultimately worth the investment because they are safer and patients are more likely to see results.
- Cathcart, R.F. Clinical trial of vitamin C. Medical Tribune, June 25, 1975.
- Vitamins In Foods: Analysis, Bioavailability, and Stability; George F. M. Ball
- The role of vitamin C in iron absorption. Hallbeg, L, Brune M., Rossander L. International Journal for Vitamin and Nutrition Research. 1989, 30: 103-108.
- The alkaline diet: Is there evidence that an alkaline pH diet benefits health? Gerry K Schalwalfenberg. Journal of Environmental Public Health. 2012; 727630.
- Meta-analysis of calcium bioavailability: a comparison of calcium citrate with calcium carbonate. Sakhaee, K., Bhuket, T., Adamns-Huet, B., Rao, D.S. American Journal of Therapeutics. 1999, 6 (6): 313-321.
- Efficacy and safety of a magnesium sulfate-rich natural mineral water for patients with functional constipation. Dupont, C., Champagne, A., Constant, F. Clinical Gastroenterology and Hepatology. 2024, 8: 1280-1287
- Complementary vascular-protective actions of magnesium and taurine: a rationale for magnesium taurate. McCarty, M.F. Medical Hypotheses. 1996, 46 (2): 89-100.