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Coffee Calcium Controversy

February 1, 2011 Written by JP    [Font too small?]

This past weekend I was catching up with my parents. They mentioned that they had attended a women’s health seminar hosted by a local physician. One of the points made by this particular speaker was that calcium supplements should never be taken with coffee. She went on to explain that coffee impairs the absorption of this essential mineral and could be counterproductive for anyone attempting to support bone mineral density. Since calcium supplements and coffee are prevalently used these days, I decided to take a look at what the medical literature has to say about this timely topic.

It comes as no surprise to me that I’m not the first person to address this issue. When I looked at a variety of medical and nutritional resources, I found various points of view about the wisdom of consuming coffee in relation to fracture and osteoporosis risk. In many instances, the opinions expressed appeared to be tinged by the overall philosophy that the authors held. Some sources, who discourage coffee use in general, emphasized the worst case scenario. Those with a financial stake in the sale of coffee predictably downplayed the potential for harm. Most mainstream authorities typically aligned themselves with a middle of the road position: moderation is the key to all things. Given this reality, I think it’s only fair to share my own bias. I’m a coffee drinker and I often promote the health benefits of this traditional beverage. But I also try to balance my reporting about coffee with information about risks that may accompany regular use.

The best study to date relating to coffee and calcium absorption was published 12 years ago in the obscure journal Isotopes in Environmental and Health Studies. The experiment in question evaluated the relative intestinal absorption of calcium coming from three distinct sources: a) 500 ml or about 17 oz of fresh milk; b) a test meal comprised of “250 g curd, 150 g yogurt, 2 slices of pineapple, 2 breakfast rolls, 2 cups of coffee, 10 g of coffee cream, 20 g butter, 50 g jam and 20 g honey”; c) a calcium supplement (lactogluconate). All three of the calcium sources were administered to 8 healthy, middle-aged volunteers on separate occasions and on an empty stomach. The findings of this unique trial revealed that the calcium supplement was absorbed best (28.7% absorbed fractions), the fresh milk registered at 24% and the test meal at 17.9%. (1)

Before we jump to any conclusions about the impact of coffee on calcium absorption based on the prior study, consider this: A Belgian trial published in 1996 examined the influence of various food components (coffee, pectin, Vitamin C and wheat bran) on mineral absorption. The minerals that were examined in this experiment were calcium, iron and zinc. Vitamin C was deemed the only positive influence on mineral bioavailability. Of the three remaining food elements, wheat bran was found to have the most detrimental effect on mineral absorption. (2)

There’s also the issue of caffeine and/or coffee and overall “calcium economy” – a term that quantifies the impact of caffeine and/or caffeinated coffee on calcium balance in the body. According to the research, the bottom line here is that one should consume slightly more calcium (~40 mg) for every cup of caffeinated coffee you drink. This alone can be accomplished quite simply by adding a dash of milk or milk substitute to each cup of java. In our home this means pouring in a few ounces of fortified, unsweetened almond milk. (3,4,5)

Coffee Consumption Lowers Plasma B-Vitamin Concentrations

Source: Clinical Chemistry. 2008;54:1489-1496. (link)

All of this is not to say that high coffee consumption never poses negative consequences on bone structure or fracture risk. Certain genotypes, such as “rapid metabolizers” of caffeine may need to be more mindful of the effects of caffeinated coffee on bone mineral density. In my review of the most recent publications pertaining to this controversial topic, I found a number of papers indicating that high coffee intake may increase the risk of osteoporosis in select populations. This is especially true in women with a calcium intake of less than 700 mg/day. But it’s also important to note that some other epidemiological examinations reveal very different outcomes ranging from a mild protective effect to no influence at all in relation to coffee use and skeletal health. (6,7,8,9,10,11,12)

Something that’s rarely discussed in the calcium-coffee debate is the role that homocysteine plays in the global picture. Elevated homocysteine, an amino acid found in the blood, is associated with a greater risk of fractures and osteoporosis. Some research estimates that regular coffee consumption may raise homocysteine levels by up to 20%. The mechanism behind this phenomenon likely has to do with a reduction in the circulating levels of vital nutrients, including folic acid and Vitamin B12. A diet rich in B-vitamins and B-vitamin supplements are considered to be the first-line treatment for elevated homocysteine. (13,14,15,16,17,18,19)

Based upon the data that I’ve uncovered, my suggestion is as follows: If you drink coffee, make sure to consume optimal levels of calcium via diet and supplementation. Taking calcium supplements apart from coffee probably aids in absorption. But it’s not absolutely essential that you drink milk or supplement with calcium on an empty stomach. Just make sure to compensate for the reduced bioavailability that accompanies meals and snacks containing a variety of foods including coffee, fiber-rich fruits and vegetables and whole grains. Last but not least, I think it’s a good idea to supplement with extra B-vitamins or a high-potency multivitamin/mineral supplement if you drink multiple cups of coffee daily. These added considerations are well worth the effort. What’s more, they may just allow you to derive the numerous health benefits and pleasure of drinking coffee without putting you at unnecessary risk for fractures and osteoporosis.

Be well!


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Posted in Bone and Joint Health, Food and Drink, Nutrition

7 Comments & Updates to “Coffee Calcium Controversy”

  1. Rahel Weiguny Says:

    Best article about a discussion about a serious topic. Was always afraid to drink coffee due to by osteoporosis and this is the first one that is written based on objective studies that are nit influenced by any financial source and that gives advice what else a woman can do for her bones. Thanks!!

  2. JP Says:

    Thank you, Rahel!

    Be well!


  3. Mark Says:

    Being a dedicated coffee drinker throughout the day I read this article with much interest. If one supplements, I’m thinking it would be advisable to take those supplements in smaller dosages during the day. Or are the effects of the full dosage in the morning enough to carry you through the day?

  4. JP Says:


    In most instances this is probably advantageous. Many nutrients, especially the water-soluble variety, have a limited half life in our system. Spreading out the dosage helps to maintain meaningful plasma concentrations over the course of the day. Whenever possible, I split up my supplements in the following manner: with breakfast, lunch and dinner or a snack and before bedtime. My bedtime supplements consist of substances that don’t benefit from being taken with food i.e. blueberry extract, magnesium, etc.

    Be well!


  5. JP Says:

    Update 05/23/15:


    Cancer Epidemiol Biomarkers Prev. 2015 May 21.

    Associations of coffee drinking with systemic immune and inflammatory markers.

    BACKGROUND: Coffee drinking has been inversely associated with mortality as well as cancers of the endometrium, colon, skin, prostate, and liver. Improved insulin sensitivity and reduced inflammation are among the hypothesized mechanisms by which coffee drinking may affect cancer risk; however, associations between coffee drinking and systemic levels of immune and inflammatory markers have not been well characterized.

    METHODS: We used Luminex bead-based assays to measure serum levels of 77 immune and inflammatory markers in 1,728 older non-Hispanic Whites. Usual coffee intake was self-reported using a food frequency questionnaire. We used weighted multivariable logistic regression models to examine associations between coffee and dichotomized marker levels. We conducted statistical trend tests by modeling the median value of each coffee category and applied a 20% false discovery rate criterion to P-values.

    RESULTS: Ten of the 77 markers were nominally associated (P-value for trend<0.05) with coffee drinking. Five markers withstood correction for multiple comparisons and included aspects of the host response namely chemotaxis of monocytes/macrophages (IFNγ, CX3CL1/fractalkine, CCL4/MIP-1β), pro-inflammatory cytokines (sTNFRII) and regulators of cell growth (FGF-2). Heavy coffee drinkers had lower circulating levels of IFNγ (OR=0.35; 95% CI 0.16-0.75), CX3CL1/fractalkine (OR=0.25; 95% CI 0.10-0.64), CCL4/MIP-1β (OR=0.48; 95% CI 0.24-0.99), FGF-2 (OR=0.62; 95% CI 0.28-1.38), and sTNFRII (OR=0.34; 95% CI 0.15-0.79) than non-coffee drinkers.

    CONCLUSIONS: Lower circulating levels of inflammatory markers among coffee drinkers may partially mediate previously observed associations of coffee with cancer and other chronic diseases.

    IMPACT: Validation studies, ideally controlled feeding trials, are needed to confirm these associations.

    Be well!


  6. JP Says:

    Updated 08/08/16:


    Clin Nutr Res. 2016 Jul;5(3):180-9.

    The Association between Coffee Consumption and Bone Status in Young Adult Males according to Calcium Intake Level.

    The purpose of this study was to investigate the association between coffee consumption and bone status (bone mineral density and bone metabolism-related markers) according to calcium intake level in Korean young adult males. Healthy and nonsmoking males (19-26 years, n = 330) participated in this study. Anthropometric measurements, dietary habits, and nutrient intakes were surveyed. Bone status of the calcaneus was measured by using quantitative ultrasound (QUS). Bone metabolism-related markers including serum total alkaline phosphatase activity (TALP), N-mid osteocalcin (OC), and type 1 collagen C-terminal telopeptide (1CTP) were analyzed. The subjects were divided into two groups based on daily calcium intake level: a calcium-sufficient group (calcium intake ≥ 75% RI, n = 171) and a calcium-deficient group (calcium intake < 75% RI, n = 159). Each group was then further divided into three subgroups based on daily average coffee consumption: no-coffee, less than one serving of coffee per day, and one or more servings of coffee per day. There were no significant differences in height, body weight, body mass index, energy intake, or calcium intake among the three coffee consumption subgroups. QUS parameters and serum 1CTP, TALP, and OC were not significantly different among either the two calcium-intake groups or the three coffee consumption subgroups. Our results may show that current coffee consumption level in Korean young men is not significantly associated with their bone status and metabolism according to the calcium intake level. Be well! JP

  7. JP Says:

    Updated 10/30/16:


    Am J Med. 2016 Sep 15.

    Associations of Coffee, Tea, and Caffeine Intake with Coronary Artery Calcification and Cardiovascular Events.

    BACKGROUND: Coffee and tea are 2 of the most commonly consumed beverages in the world. The association of coffee and tea intake with coronary artery calcium and major adverse cardiovascular events remains uncertain.

    METHODS: We examined 6508 ethnically diverse participants with available coffee and tea data from the Multi-Ethnic Study of Atherosclerosis. Intake for each was classified as never, occasional (<1 cup per day), and regular (≥1 cup per day). A coronary artery calcium progression ratio was derived from mixed effect regression models using loge(calcium score+1) as the outcome, with coefficients exponentiated to reflect coronary artery calcium progression ratio versus the reference. Cox proportional hazards analyses were used to evaluate the association between beverage intake and incident cardiovascular events.

    RESULTS: Over a median follow-up of 5.3 years for coronary artery calcium and 11.1 years for cardiovascular events, participants who regularly drank tea (≥1 cup per day) had a slower progression of coronary artery calcium compared with never drinkers after multivariable adjustment. This correlated with a statistically significant lower incidence of cardiovascular events for ≥1 cup per day tea drinkers (adjusted hazard ratio 0.71; 95% confidence interval 0.53-0.95). Compared with never coffee drinkers, regular coffee intake (≥1 cup per day) was not statistically associated with coronary artery calcium progression or cardiovascular events (adjusted hazard ratio 0.97; 95% confidence interval 0.78-1.20). Caffeine intake was marginally inversely associated with coronary artery calcium progression.

    CONCLUSIONS: Moderate tea drinkers had slower progression of coronary artery calcium and reduced risk for cardiovascular events. Future research is needed to understand the potentially protective nature of moderate tea intake.

    Be well!


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