A steaming cup of tea or coffee is a morning ritual for most of us. That also makes it a convenient moment to pop our daily vitamin supplements. But it turns out the drink you choose to wash them down with has a lot to do with it how much of the goodness your body actually soaks up.
Sorry to break it to you, but your morning brew may not be ideal. While we rely on caffeine for a jolt of energy, it can also interfere with how well some vitamins and minerals are absorbed by the body.
Here are six vitamin and mineral supplements that you should definitely not take with tea or coffee…
Iron
Iron is essential in making haemoglobin, a protein in red blood cells that helps carry oxygen from the lungs to the rest of your body. It plays a key role in energy production, hormone synthesis, strengthening the immune system and even neurological development.
According to the NHS, women who lose a lot of blood during their monthly period are at higher risk of iron deficiency anaemia and may need to supplement. The trouble is, “caffeine can inhibit the absorption of iron supplements – the same goes for the iron in your food,” says Rhian Stephenson, nutritional therapist and founder of Artah. “Studies have shown that coffee and tea intake can also inhibit iron from food sources, so if you're anaemic or pregnant and working to get your levels up, it's useful to pay particular attention to this.”
Several studies have found that polyphenols, especially tannins, can also play havoc with your iron supplement. These plant compounds found in tea and coffee essentially bind with iron during digestion, reducing the amount that your body absorbs. Switching to decaffeinated tea or coffee sadly isn't the answer, as the polyphenols still remain intact.
This is especially true of non-heme iron found in plant foods such as nuts, whole grains and leafy greens, says Rhian. "This is because of their polyphenol content, which can transform non-heme iron into a form that is non absorbable," she notes. "There is a lesser effect on heme [animal-based] iron.”
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Vitamin D
Scientists have found that vitamin D influences over 200 genes in our body. It keeps our immune systems healthy, regulates our sex hormones and is essential for the body to absorb calcium in order to strengthen bones and teeth.
It is also key for regulating sleep. “Low vitamin D levels increase the risk of sleep difficulties, including shorter sleep duration, increased nocturnal awakenings and delayed sleep onset,” Rhian explains.
“Some studies have shown that we can experience a caffeine-induced decrease in vitamin D receptor expression, resulting in lower levels in those who drink more caffeine," she adds.
In particular, a joint study by Creighton University in Nebraska and the University of Miami, Florida, found that caffeine reduced the expression of vitamin D receptors on osteoblasts – the cells in our bodies responsible for producing bone.
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Vitamin C, B vitamins, magnesium & potassium
There's not much that vitamin C can't do. It helps the body produce collagen, a protein used to make cartilage, ligaments, skin and blood vessels. Vitamin C also helps with wound healing and is a potent antioxidant, which protects your body's DNA from damaging free radicals.
Meanwhile, B vitamins help your body's cells (skin, blood and brain cells) to develop and convert food into energy.
While they have very different functions, B vitamins (thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate, and cobalamin) and vitamin C are all classed as water-soluble vitamins, meaning that your body can’t store them so they are easily lost through urine.
Given caffeine is a stimulant, it also increases the production of urine so some vitamins and minerals don't absorb as well before being flushed out. Rhian points out that “because caffeine has a diuretic effect, it can increase the excretion of B vitamins and vitamin C,” before your body has had a chance to absorb their benefits.
She adds that caffeine has a similar effect on electrolytes such as magnesium and potassium – minerals that help with sleep, metabolism, healthy heart function and keeping the body hydrated.
How should you take your vitamin supplements?
Ideally, take your vitamin supplements with a glass of water. If you're a coffee lover, Lucy Goff, founder of Lyma, recommends “leaving 30 minutes before or after caffeine” to take your supplement.
The exception is iron. “It's important to leave a one to two hour gap between your iron supplements and your cup of coffee or tea,” Rhian notes. And try knocking them back with orange juice, as vitamin C helps the body to absorb iron better.
You can also replenish your magnesium and potassium levels by adding electrolytes to a glass of water. Good options include Artah Cellular Hydration and Ancient + Brave True Hydration Jar.
Disclaimer: Vitamin supplements are not a replacement for a healthy balanced diet. Before supplementing, it's best to consult with your doctor and/or a registered dietitian.
For more from Fiona Embleton, GLAMOUR's Associate Beauty Director, follow her on @fiembleton.