Optimizing your health by taking several food supplements at the same time has become a common reflex. However, certain very widespread associations can actually reduce the effectiveness of the molecules consumed, or even be counterproductive.
“As I often tell my patients: accumulating food supplements is tempting, but you should rather focus on precise targeting, rather than quantity.“, recalls Dr Aurélien Tesson, pharmacist.
Here are all these very popular associations… and yet counterproductive.
Multiplying supplements: a bad idea?
Magnesium, vitamin C, zinc, iron, collagen… Many French people consume several food supplements simultaneously, thinking of maximizing the benefits.
“The problem is that these products are not always designed to be taken together. Certain combinations may compete or disrupt their absorption“, explains Aurélien Tesson.
Result: the effects are reduced here, or even non-existent, even when taking supplements regularly.
Iron and zinc: direct competition
This is one of the most problematic combinations, because iron and zinc use similar absorption mechanisms at the intestinal level. Taken at the same time, they enter into competition, thus reducing their respective assimilation.
“We may think we are doing well by correcting several deficiencies at once, but in the end, we absorb less of each“, indicates the doctor of pharmacy.
His advice: space out the doses by at least 2 to 3 hours.
Calcium and magnesium: not always complementary
Often combined in “anti-fatigue” or “anti-stress” supplements, calcium and magnesium can nevertheless interact. In high doses, calcium can even reduce the absorption of magnesium from the intestine.
“This is not necessarily a bad combination, but it must be balanced. Otherwise, we lose part of the desired effect, particularly on fatigue or cramps.” warns the expert.
Tea, coffee and iron: a reflex to avoid
This is a very common error. And yet it is not without consequences! Here, the tannins present in tea and coffee greatly reduce the absorption of iron, particularly of plant origin.
“Taking an iron supplement with your morning coffee is probably one of the worst reflexes in terms of effectiveness“, alerts the specialist.
The pharmacist’s advice: avoid tea and coffee within 1 to 2 hours of taking it.
Zinc and copper: a possible imbalance
Prolonged zinc supplementation can lead to a decrease in copper in the body. However, this imbalance can have very serious consequences, particularly on immunity or the production of red blood cells.
“This is typically the kind of effect that we do not suspect, but which can appear with poorly adapted supplementation over time.“, indicates the doctor of pharmacy.
Vitamin C and copper: a little-known interaction
In high doses, vitamin C can also interfere with copper absorption. A little-known threat, while vitamin C is often taken daily and sometimes in high doses.
“Also remember to favor liposomal vitamin C, which is better absorbed than so-called classic vitamin C”, specifies the practitioner.
Collagen and proteins: a diluted effect?
Collagen (a protein with many benefits for the skin and joints) is often consumed in addition to a diet already rich in protein.
“However, if the overall protein intake is sufficient, adding collagen does not necessarily have a significant impact. The effect can be diluted“, admits the specialist.
The benefit of this supplement therefore depends on your overall eating routine.
The importance of the right “time”
Beyond these known associations, the time of taking is essential. Indeed, certain supplements must be taken on an empty stomach for better absorption (like iron), while others need to be included in a complete meal (fat-soluble vitamins like A, D, E or K).
“Timing is often as important as the choice of the supplement itself“, recalls Dr Aurélien Tesson.
The key role of the pharmacist
Faced with the proliferation of food supplements on the shelves – and the errors made when using them – contacting a health professional therefore remains essential.
“Our role is precisely to avoid these ineffective associations and to adapt supplementation to real needs.“, concludes the doctor of pharmacy.