This morning as I poured a generous serving of half and half into my coffee I started wondering how much calcium this daily ritual was providing me.  I’m getting close to 30, which is the age when women stop increasing their bone density, and so my goal is to get 1300mg of calcium each day. With that number in mind I began to scan the half and half container to see how much of my goal I’d accomplished before breakfast.

The answer is: the box doesn’t tell you.  The container claims that I’m getting 4% of my daily calcium from every 2 tablespoons of half and half I consume, but that statement is ludicrous.  Calcium is one of the most variable nutrients in terms of how much an individual needs.  Babies require less than children, but children require more than adults, and women require more than men; the amount of calcium you need varies enormously depending on your age and gender.  So, the question becomes, what segment of the population is that 4% written for?

My first guess was teenage boys.  I had this memory from one of my nutrition classes last year that when the RDAs (recommended dietary allowance) for micro-nutrients were established they were based on teenage males, simply because they tend to have the greatest needs (just think about how fast they grow).  There are a couple of problems with this guess though.  First off, labels are based on a 2000-calorie-a-day intake.  Teenage boys need significantly more calories than that, up to 50% more.  Is the 4% calcium based on the RDA for teenage boys or on a 2000 calorie diet?  Or neither?

To learn more I did a little internet research.  According to the UCSF Medical Center a single tablespoon of half and half contains 16mg of calcium.  Since the serving size of my half and half was two tablespoon I should be getting 32mg of calcium in each serving.  32mg is 4% of 800mg.  To me 800mg per day seemed like a low number for the RDA for calcium, at least for women.  This made me think that I was correct in assuming that the percentage on the container was based on the amount needed for teenage boys.  I decided to look up the recommended amount of calcium for teenage boys to see if it matched.

According to the Pediatric Nutrition Handbook (a publication by the American Academy of Pediatrics) teenagers should get 1300mg per day: the exact amount I’m shooting for.  That ruined my teenage boy hypothesis.  Either the percentage was based on some other RDA or the people who write the labels for half and half are very bad at math.  My half and half is claiming to give me 4% of my daily calcium needs but providing me with 32mg.  That’s 2.46% of both my daily needs and the daily needs of teenage males.  So, who does need 800mg of calcium per day?

I decided to check another resource, a 2000 page tomb called Modern Nutrition in Health and Disease that is my go-to guide for all things nutrition.  According to this book the Adequate Intake for calcium can range from 1000-1300mg in adults, and the recommended amount for my age group and gender is listed as 1200mg per day.  800mg per day is that amount listed for children ages 4-8 years of age.  In that case, why is 800mg per day the amount my half and half is encouraging me to consume?  In my opinion this is shockingly low.  As well as shockingly random.

I didn’t want to generalize too much.  Maybe the half and half folks really are just bad at math.  I checked a half gallon of low fat milk and a container of raspberry yogurt in my fridge to compare and contrast with the half and half.  All three were different brands so I figured it was a pretty representative sample of dairy products.  However, all three seemed to be basing their percentages on a total need of between 800 and 900mg of calcium per day depending on whose calcium-in-food table you looked at.

Here’s something else I found out, the amount of calcium the average young American female is actually consuming is just about 800mg per day.  According to a study published in The Journal of the American College of Nutrition in 2006 the average amount of calcium consumed by girls age 11-19 is 814mg per day.  The National Health and Nutrition Examination Survey 1999-2000 found similarly low levels with average calcium intakes of 1,081 and 793mg/day for boys and girls ages 12-19 years, respectively; 1,025 and 797 mg/day for men and women 20-39 years; and 797 and 660 mg/day for men and women ≥60 years.

I’m not saying that all these people were getting close to 800mg of calcium per day because they were misled by the labels of their dairy products.  In fact, I’m guess that most of them never attempted to determine their calcium needs by using label recommendations.  However, I am saying that even if they did use the labels on food packages they would still get it wrong and think that they were getting an adequate amount of calcium, and that is disturbing.

Scientists and doctors agree that up to 2500mg of calcium per day is perfectly safe.  The NIH (National Institute of Health) lists 2500mg as the Upper Limit for calcium.  That is, the most calcium a person can take before they have an adverse reaction.  If that’s true, why are we listing the lowest possible needs on our food containers?  You’re much more likely to be hurt by consuming too little calcium than by consuming too much.  And it seems obvious that getting too little calcium is a much more widespread problem, at least in this country.

If you’re reading this blog I’m guessing you need about 1200mg of calcium per day.  That means you need to take the percentage on the container and reduce it by 1/3 to find out what percentage of your daily needs you really are fulfilling.  Making sure you’re getting enough calcium may be frustrating, especially since labeling laws seem to be working against people with that goal.  Just remember, the rewards for your hard work and revival of those dormant math skills are healthy bones and an escape from osteoporosis in later life.