Caffeine has a mild diuretic effect, which leads to an increase in urination. As a result, water-soluble vitamins, such as B-vitamins and vitamin C can be depleted due to fluid loss. Research also demonstrated that the higher the level of caffeine, the more it interfered with vitamin D absorption.
The tannins and caffeine can interfere with the absorption of many vitamins and minerals, especially iron. Caffeine also increases urination, which can decrease the concentration of water-soluble vitamins (B-complex and C). So, wait an hour after your morning brew to take supplements.
There are other studies that found coffee drinkers tend to have higher homocysteine levels which is a surrogate marker for b12 (and folate) deficiency. Overall it seems clear that coffee and caffeine increase excretion of B vitamins, including B 12.
[1] People who regularly take medications that suppress stomach acid for conditions like gastroesophageal reflux disease (GERD) or peptic ulcer disease—such as proton-pump inhibitors, H2 blockers, or other antacids—may have difficulty absorbing vitamin B12 from food.
What Causes Vitamin B Deficiency? Here's a roundup of 4 of the top causes of vitamin B deficiency: a non-balanced diet, excessive alcohol consumption, various medications (such as proton-pump inhibitors, or PPIs), and gut malabsorption conditions.
Coffee also seems to impact on the metabolism of some B vitamins like thiamine. Vitamin B12, though, looks like being a possible exception – indeed, caffeine's stimulation of stomach acid production may actually assist, instead of compromise, your body's B12 absorption.
This is where gut health comes into play since it is important for proper vitamin and nutrient absorption. Vitamin B12 gets absorbed in the stomach, thanks to a protein known as intrinsic factor. This chemical attaches to the vitamin B12 molecule, allowing it to enter the bloodstream and cells more easily.
Diet. Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet. A diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foods can become deficient.
Avoid taking antacids, dairy products, tea, or coffee within 2 hours before or after this medication because they may decrease its effectiveness.
It's not advised to take vitamin C and vitamin B-12 at the same time, says Litt. That's because high doses of vitamin C can reduce the amount of vitamin B-12 that's absorbed and metabolized by the body, she says. Be sure to take vitamin C at least two hours after vitamin B-12.
Some beverages, including coffee, contain substances that could interfere with the absorption of some of the nutrients in your vitamin. It's better to drink your coffee about 15 minutes before or a few hours after you take your vitamin.
How to raise your B12 levels fast. The most common way to treat B12 deficiencies is by adjusting your diet. If this is unsuccessful, vitamin supplements may be recommended. If you're looking to boost the amount of vitamin B12 in your diet, you should eat more animal products, like meat, seafood, dairy and eggs.
There are certain foods that also need a cut-down in case of vitamin B12 deficiency. “Some foods and drinks can interfere with vitamin B complex intake like alcohol, caffeine and processed foods, etc should be avoided completely,” Shah added.
Your body doesn't produce vitamin B naturally, so your intake depends on your diet and any supplements you take. As vitamin B and magnesium don't affect each other's absorption inside your body, you'll find that many supplements combine the two.
Additionally, certain food products such as tea, coffee, raw fish, and shellfish contain thiaminases - enzymes that destroy thiamine. Thiamine deficiency can affect the cardiovascular, nervous, and immune systems, as commonly seen in wet beriberi, dry beriberi, or Wernicke-Korsakoff syndrome.
"As you intake more water you can begin to flush water soluble vitamins and minerals," Dr. Kinney told INSIDER. "Water soluble vitamins, such as the B Vitamins (B1, B2, B3, B6 & B12) & vitamin C, are not stored long term and may be excreted with excess water intake if you're not taking in proper supplementation, too.
While tannins in tea can have an effect on calcium absorption, it is minimal and can be handled by drinking a glass of milk daily. Caffeine is a diuretic and, as such, the water-soluble vitamin B12 would be eliminated from the system before it could be fully utilized.
“The most common vitamin B deficiency is the B12 vitamin and sometimes folate, which is B9,” says Teems. “B12 helps make healthy red blood cells, which keep the nervous system working properly, and folate is crucial in the development of DNA.