But a report published by the health magazine verywellhealth indicates that not all supplements combine well with coffee, and sometimes consuming them together may prevent the supplement or vitamin from being absorbed by the body or impair its effectiveness. Here are five popular nutritional supplements that should not be combined with coffee according to verywellhealth and the reasons why.
1. Iron
The iron is responsible for the transfer of oxygen in the blood and supports cell function. In cases of deficiency, supplements are sometimes required, but drinking coffee together with them may reduce absorption.
The reason for this lies in the tannins and polyphenols in coffee, which bind to iron and make it difficult for the body to absorb it. Studies show that the effect of coffee depends on the time of drinking – therefore it is recommended to take an iron supplement at least two hours before or after the coffee.
2. Water-soluble vitamins (complex B and C)
Caffeine is a mild diuretic, so drinking coffee in large quantities increases urination and may lead to loss of nutrients. This condition may reduce the effectiveness of B vitamins (including B1, B6, B7 and B12) and vitamin C, which are washed out of the body. Since the body does not store water-soluble vitamins, it is recommended to take them at different times from drinking coffee, to improve absorption.
3. Vitamin D and calcium
Here, too, coffee may interfere: coffee may reduce the absorption of both vitamin D and calcium. Studies indicate that high caffeine consumption is associated with lower levels of vitamin D. Coffee may reduce the number of receptors needed to absorb vitamin D, which also works to promote calcium absorption and maintain bone health. In addition, caffeine increases the loss of calcium through the urine and limits absorption in the intestines.
Although moderate consumption of coffee is not considered harmful to bones, those who are at risk of calcium deficiency or osteoporosis should take the supplements at other times than the hours of coffee consumption.
4. Magnesium and zinc
The polyphenols and tannins in coffee can also bind to other essential minerals, including magnesium and zinc, thus reducing their absorption in the body. Beyond that, the changing effect of coffee increases the loss of nutrients through the urine, so the amount of magnesium and zinc available to the body decreases. Magnesium is essential for muscle function, nervous system and heart health, while zinc helps the immune system, wound healing and skin and hair health.
To maintain normal levels of these two minerals, it is recommended to take the supplements separately from the coffee – at least two hours before or after – and thus allow the body to utilize them optimally.
5. Melatonin
Melatonin is a natural hormone that is produced in the body and regulates the circadian rhythm – that is, the cycles of wakefulness and sleep. Its production increases as darkness falls and it helps to fall asleep. Melatonin is also given as a supplement and is used to improve the quality of sleep or to deal with jet lag.
The problem: caffeine works the other way around. As a stimulant, it maintains alertness and inhibits the action of melatonin, especially if consumed in the evening or close to sleep. Studies show that drinking coffee even a few hours before bed can reduce the secretion of melatonin and make it harder to fall asleep.
To avoid a disturbance, it is recommended to separate the consumption of coffee and the melatonin supplement by several hours – and in fact, to avoid caffeine at least six hours before bedtime.
It’s all a matter of timing
verywellhealth experts emphasize that the key to preventing unwanted effects between nutritional supplements is timing. It is recommended to take your vitamins or supplements separately from the cup of coffee, preferably at least a few hours later. This way you can minimize the possible impact and ensure optimal absorption of the nutrients important to the body.