By Carla Gerryts — Registered Dietitian (RD SA)
Walk into any pharmacy, health shop, or even scroll through social media, and you will be met with shelves and screens filled with promises and options. It can be very overwhelming. So, is it any wonder that patients and healthcare professionals alike ask: to supplement or not to supplement?
In a fast-paced world where convenience often trumps consistency, the idea that health can be optimised one capsule at a time is understandably attractive. However, when it comes to supplementation, context is everything. It starts from the bottom up: what is your current diet looking like and do we have any biochemical or clinical data pointing towards a nutrition deficiency?
Let us consider some of the most commonly used supplements:
Vitamin D is frequently recommended, and for good reason. Limited sun exposure, indoor lifestyles, sunscreen use, and darker skin pigmentation can all contribute to low levels. Vitamin D plays a role in bone health, immune function, and muscle strength. However, it is also fat-soluble, meaning that excess amounts are stored rather than excreted. The appropriate dosing matters and supplementation should ideally be guided by blood levels. Vitamin D is best absorbed with a meal containing fat, not on an empty stomach with a morning coffee.
Iron is another commonly self-prescribed supplement, particularly among women. Although iron deficiency is prevalent, unnecessary supplementation can cause gastrointestinal discomfort and oxidative stress. Iron is best absorbed on an empty stomach but is often poorly tolerated. Taking it with vitamin C can improve absorption, while tea, coffee, calcium, and high-fibre foods hinder absorption. As a rule of thumb, iron should only be supplemented when the deficiency has been confirmed and monitored.
Magnesium has gained popularity for stress, sleep, muscle cramps, and headaches. Different forms exist, each with different applications and tolerability. Magnesium is generally better tolerated with food, and many people find it helpful when taken in the evening due to its calming effects. Although relatively safe, excessive doses can cause digestive side-effects such as diarrhoea.
Vitamin B12 deserves special mention, particularly in older adults, vegetarians, and people with gastrointestinal conditions. Absorption is based on an intrinsic factor and adequate stomach acid, both of which decline with age and certain medications. Timing is less critical, but consistency is key. In some cases, injectable forms may be required.
Omega-3 fatty acids, commonly taken for cardiovascular, inflammatory, and mental health benefits, are best absorbed with meals containing fat. Quality, formulation, and dose are important considerations, as is ensuring that they complement dietary intake rather than replacing dietary sources altogether.
The most overlooked aspects of supplementation are timing and interactions with other supplements or medications. Some supplements compete for absorption, while others enhance each other. Calcium and iron, for example, should not be taken together. Fat-soluble vitamins require dietary fat. Certain supplements may interfere with medications or exacerbate existing conditions. Taken incorrectly, even the ‘right’ supplement may become ineffective.
More is not always better. Excessive supplementation can lead to toxicity, nutrient imbalances, or a false sense of security that distracts from foundational health behaviours. And while ‘natural’ is a popular selling point, it is not synonymous with safe. Herbal supplements are biologically active and can interact with medications, affect liver function, or alter absorption of nutrients.
From a clinical perspective, supplementation should be individualised, evidence-based, and purposeful. Blood results, dietary intake, medical history, symptoms, and lifestyle context all matter. A supplement used for a specific indication, at the correct dose, for an appropriate duration, can be a powerful add-on to your current health strategy.
Supplements to keep your eye out for in 2026? Creatine and inositol. These two supplements have gained a lot of traction for a variety and for different reasons. Between the two of them, we can address insulin resistance, maintain muscle mass during a weight loss process and even support mental health.
Perhaps the most important question is not what to supplement but why. And if that question cannot be answered clearly, it may be time to pause, reassess, and remember that, while supplements may be very appealing, wellness remains refreshingly simple: eat well, move regularly, sleep adequately, manage stress, and supplement thoughtfully, when truly needed.