Caffeine’s Effects On Nutrients

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Among the antinutrients found in foods and supplements, caffeine is a significant one because it can influence many nutrients and the body in so many ways. We’ll be looking at what those effects are in this article. And when it comes to caffeine, it’s not only about what it hinders in absorption but also its effects once it’s in the body, making it a full-blown Antinutrient!

Caffeine’s Effects on Vitamin C

Since vitamin C is one of the most essential vitamins, we’ll look at this first. Vitamin C is the primary supporting nutrient for the immune system but it is also responsible for the absorption, assimilation, and activation of many minerals, as well as collagen. ^{1 2} Without it, these cannot be used as effectively by the body, especially for calcium, iron, magnesium, and other minerals. ³ It’s no wonder why some experts such as Dr. Suzanne Humphries, calls osteoporosis Scurvy of the bones as the body needs vitamin C. ⁴ And it needs to be whole food vitamin C as synthetic (ascorbic acid) is, according to Dr. Robert Thompson, author of The Calcium Lie 2, is just the “wrapper.” Learn more about that in What is Vitamin C? and WHY NOT (SYNTHETIC) ASCORBIC ACID?

According to a report from Consumer Affairs, caffeine can both hinder the absorption of vitamins and minerals as well as increase their excretion from the body. ⁵ This can be crucial as some with mineral absorption and retention issues, like those with osteoporosis can’t afford to lose more bone than what may already be occurring.

Here is a statement from the senior editor of Food Pyramid(dot com)

Drinks and food containing caffeine such as coffee, tea, cola drinks and chocolate can inhibit the absorption of vitamin C. Vitamin C is water-soluble and can be removed through your urine. Since too much caffeine consumption may cause a frequent urination it can cause your body to become depleted of Vitamin C.
Food Pyramid – 25 Jan, 2010

There it is; the double whammy! Caffeine not only hinders the absorption of vitamin C but also can cause frequent urination leading to a depletion of this vital nutrient.

A statement from Holland & Barrett said:

Caffeine interferes with the absorption of vitamin C, meaning that you might not be getting the full benefits of your healthy diet if you regularly drink coffee, tea or other caffeinated beverages alongside meals.

Also:

When you sip a cup of coffee alongside an orange as a morning snack, you are risking the caffeine from the coffee preventing proper absorption of the orange’s vitamin C content. Caffeine increases blood flow throughout your body including to your kidneys, causing them to filter through waste faster thus having a diuretic effect – making you need to urinate. The vitamin C from the orange might be eliminated in your urine before your body has had a chance to absorb its goodness.

And

Caffeine is a stimulant which wakes up your digestive system by encouraging muscle contractions along your intestinal tract. This enables waste to be eliminated faster than if you hadn’t consumed a caffeinated drink. While this can be good to keep you regular, it can also eliminate vitamins and minerals along with other waste before they’ve had a chance to be fully absorbed into your body.
https://www.hollandandbarrett.com/the-health-hub/vitamins-and-supplements/vitamins/vitamin-c/could-coffee-be-sabotaging-your-vitamin-c-levels/ 1 June 2023

So, again, we have a further affirmation that caffeine affects both how much we benefit from vitamin C intake as well as the loss through faster elimination.

Caffeine’s Effects on Vitamin D

There are other vitamins caffeine affects. In this citing from LiveStrong(dot com), it is mentioned that caffeine also affects vitamin D. Why is that important?
As we previously discussed on the Vitamin D page, this hormone is needed to aid calcium into the bloodstream where, when directed properly, can move calcium to the bones, teeth, and nails. Here is what Dr. Nicola Perry had to say about caffeine’s effect on vitamin D.

In a collaborative study at Creighton University in Nebraska and the University of Miami, Florida, researchers showed that caffeine may interfere with vitamin D absorption. The results, published in the “Journal of Steroid Biochemistry and Molecular Biology,” demonstrated that the higher the level of caffeine, the more it interfered with vitamin D absorption. The study suggested that caffeine did this by reducing the expression of vitamin D receptors on osteoblasts in the body — the cells responsible for producing bone.

Does Caffeine Affect the Absorption of Vitamins or Minerals?/Dr. Nicola Perry

Healthcare-Online also addresses caffeine’s effects on vitamin D, saying

Ingesting caffeine in your body can inhibit vitamin D receptors, which can interfere with the way your body absorbs it. Vitamin D plays an important role in the absorption of calcium, which is why you will have a low bone mineral density when you have a vitamin D deficiency. This also increases your risk of osteoporosis.
https://www.healthcare-online.org/does-caffeine-affect-vitamin-absorption.html

Caffeine’s Effects on Calcium:

In the same article from Dr. Parry at LiveStrong, a statement was also made about caffeine affecting calcium. Though osteoporosis is not a calcium deficiency, ⁶ calcium is important for the bones. Though not the most important mineral for bone health, the bones do hold about 99% of the calcium in the body. ⁷

Caffeine can also interfere with the absorption of calcium. A study published in the journal “Osteoporosis International” showed that just a cup of coffee can slightly reduce calcium absorption in the body and increase its loss in urine due to its diuretic effect.
Does Caffeine Affect the Absorption of Vitamins or Minerals?/Dr. Nicola Perry

From Healthcare-Online (dot org) ⁷

Consuming too much of caffeine would make you excrete calcium through urine. Your body loses about 5mg of calcium when you drink a cup of coffee or consume about 150mg of caffeine. The effect can take place even several hours of ingesting caffeine. Studies have also found that postmenopausal women lose more bone in the spine when they drink 300mg of caffeine a day as compared to those who consume less. Moreover, caffeine can also affect the way your body absorbs calcium through the intestinal tract, which increases your risk of hip fractures and other injuries.

Holland & Barrett support the statements in one of their articles on caffeine. ⁸ But other sources have also supported such statements. For example, a statement by ResearchGate stated:

Caffeine can cause nutrient depletion of important nutrients, like vitamin B6, and interfere with nutrient absorption of essential minerals, including calcium, iron, magnesium and B vitamins.
TY – JOUR/AU – Wolde, Tsedeke/PY – 2014/01/01/SP -/T1 – Effects of caffeine on health and nutrition:A Review/VL – 30/ER –

Healthcare-online (dot org) stated

Caffeine can have a major impact on certain vitamins and minerals, such as the following: Calcium: Consuming too much of caffeine would make you excrete calcium through urine. Your body loses about 5mg of calcium when you drink a cup of coffee or consume about 150mg of caffeine. The effect can take place even several hours of ingesting caffeine.
https://www.healthcare-online.org/does-caffeine-affect-vitamin-absorption.html

An article by Medical News Today titled “Does caffeine contribute to osteoporosis?” read that although studies have produced conflicting conclusions, “According to researchers, caffeine interferes with the body’s absorption of calcium. Some experts suggest that excess caffeine might affect bone health.” It went on to say some studies in animals have shown that caffeine can affect bone growth. Caffeine given to pregnant rats led to slower bone growth in the fetuses. It also said experts suggest caffeine interferes with endochondral ossification. This is the bone remodeling process where cartilage is transmuted into new bone with the aid of calcium. ⁹ ¹⁰

Caffeine not only hinders the body’s ability to absorb calcium from food but increases how much the kidneys will eliminate calcium. Together, these actions can lower calcium levels. Something else found to affect calcium retention is the fact that consuming caffeine can also decrease the levels of inositol in the blood. Inositol plays an important role and with decreased levels even more calcium is excreted by the kidneys and less is absorbed in the intestines. ¹⁰

Dr. Naveed Saleh, MD states

For every cup of coffee consumed, 5 mg of calcium is excreted in urine and feces. The loss can occur several hours after caffeine intake. Furthermore, coffee likely mitigates the absorption of calcium and depletes bones of calcium.
Don’t drink coffee with these vitamins/Naveed Saleh, MD, MS | Published August 14, 2020

Also mentioned by Dr. Naveed was a study published in Life Sciences stating that

According to the results of a small study published in Life Sciences, women between the ages of 31 and 78 years who consumed coffee with a 6 mg/kg caffeine concentration on two separate mornings experienced urinary losses of magnesium, calcium, sodium, chloride, potassium, creatinine, and water within 2 hours of intake.
Don’t drink coffee with these vitamins/Naveed Saleh, MD, MS | Published August 14, 2020

So can caffeine affect other nutrients and their absorption and utilization in the body? Oh, yes!

Iron is one of those and though not as critical to bone remodeling as others, it is essential to the health of the body and oxygen-rich blood. This statement was made by Healthcare-Online regarding iron –

Caffeine can also affect the way your body absorbs and uses iron. Without enough iron, your body cannot produce enough red blood cells. If you drink caffeine at the time of consuming an iron food, it can lower iron absorption by 80%. Therefore, you should never drink a caffeinated beverage when you are consuming an iron-rich food or supplement.
https://www.healthcare-online.org/does-caffeine-affect-vitamin-absorption.html

Other nutrients caffeine can affect are B vitamins. Again from Healthcare-Online

B-vitamins are basically water-soluble vitamins, which means you will lose a large amount of these vitamins through frequent urination, which is a common problem associated with caffeine intake. Moreover, caffeine can also affect the metabolism of thiamine (vitamin B1) and many other vitamins. It is worth mentioning that caffeine may actually help improve the absorption of B12 because it increases production of stomach acid.
https://www.healthcare-online.org/does-caffeine-affect-vitamin-absorption.html

Some claims are made that other minerals can be affected by caffeine including the reduced absorption of copper, manganese, and zinc. Also, because of the diuretic effect of caffeine, it can lead to potassium, magnesium, phosphate, and sodium deficiency. ⁸

Written by Douglas K. Johnson – Life, Health and Wellness Coach, Herbalist, Nutritionist, Investigative Journalist, and Author

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