vii: The Chemistry Column
Beyond the bones Claire Gormley Whenever I hear ‘Calcium’ my mind immediately jumps to ‘strong bones’. That’s thanks to the highly successful Got Milk? advertisement campaign I was exposed to, growing up in the United States. I’m sure I am not alone in this. Got Milk?, along with many precursor campaigns, convinced us that the key to developing a healthy skeletal system was a daily dose of Calcium from the carton of milk on our lunch trays. It was only recently that I learned the truth behind the suggestion that drinking milk is the best way to build strong bones: the advertising campaign was designed to increase consumer demand, so that processed dairy products could be shipped to soldiers abroad (Belluz, 2015). In fact, portions of almonds, bok choy, broccoli and kale can each provide our body with more Calcium than a glass of milk, but we rarely consider these other sources because the association between Calcium and milk is so strong (Cormick and Belizán, 2019; Belluz, 2015). Now that the mental knot tying Calcium to milk has been loosened, I begin to wonder— how does Calcium contribute to our bodies beyond building strong bones? Calcium belongs to the Alkaline Earth Metals— Group two in the Periodic Table of Elements —along with Beryllium, Magnesium, Strontium, Barium and Radium. Alkaline Earth Metals are all shiny, silvery-white in their solid 32
state. Like all the others, Calcium gives away its two outermost electrons, also known as its valence electrons, to achieve its most stable form. The loss of electrons, which are negatively charged particles, creates an overall positively charged atom, also known as a cation. The Calcium cation, Ca2+, is incredibly important for plant growth and development and cell wall formation, as well as for sending intracellular messages (Helper, 2005; White and Broadly, 2003; National Institutes of Health, 2021). About 99% of the Calcium in our bodies is stored in our bones and teeth, providing them with structure and strength, hence the need to get enough Calcium in our diet to build strong bones (Lewis III, 2021; Harvard, 2021). The other 1% is needed by the blood to stimulate blood clot formation, as well as by muscle cells and neurons to activate specific cell functions (Singh et al, 2019; Lewis III, 2021). If these parts of our body are not getting sufficient Calcium, a hormone called parathyroid— one of two hormones that regulate the level of Calcium in our blood —is produced to signal our body to preserve Calcium and to stimulate our bones to release some of their stored Calcium for the blood, muscles, and neurons to use (Lewis III, 2021).
