Let's talk about the human body, with all of its imperfections. But let's not focus on them, rather let's focus on what they're made of. You and I are made from around 20 different elements, each and everyone of them (except Hydrogen) was forged in the heart of a massive star, billions of years ago.
Many billions of years ago, in our galactic neighborhood, a star much larger than our sun, ended its life in spectacular fashion, exploding in a supernova! And I understand that it might be difficult to fathom what it takes to blow up a star, so let me explain. For whatever reason, a recent unit of measure of energy has become the nuclear bomb dropped on Hiroshima. That bomb exploded with a energy of approximately 15 kilotons (15,000 lbs.) of Trinitrotoluene (TNT); the bomb detonated over the Japanese city of Nagasaki was 21 kilotons (21,000 lbs.) of TNT. Both caused horrific damage and death to the citizens of the respective cities but even the largest nuclear weapon ever created ONLY exploded with an approximate equivalent to 127,000,000,000 pounds of TNT. Now consider that an AVERAGE star is capable of exploding in a supernova that can explode with the same energy as the sun will create in it's entire 10 BILLION YEAR LIFETIME! In other words, eh, numbers, that's a 1, followed by 44 zeros! So you have an idea what that looks like... That's 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000 pounds of TNT!
But back to our imperfect bodies. Now I will admit to being far from the "average" male weight in the United States but for laughs, let's pretend I am the average 176 pound man. Of those 176 pounds, a full 115 pounds of that is Oxygen! Obviously not gaseous oxygen but bonded oxygen. According to sciencenotes.org, it's (oxygen) mainly found bound to hydrogen in the form of water. Water, in turn, makes up about 60% of the human body and participates in countless metabolic reactions. The element oxygen acts as an electron acceptor and oxidizing agent. It is found in all four of the major classes of organic molecules: protein, carbohydrates, lipids, and nucleic acids.
Let's go back a little further back in the periodic table and talk about Carbon. Atomic number of 6 and making up roughly 18% of your body weight, this element is an incredible one! Making up the most part of all organic chemistry, Carbon is in EVERY SINGLE organic molecule in your body. The carbohydrates in that bread, has carbon. The oil/fat in cheese on that pizza, has carbon. The proteins that make up the amino acids, has carbon and the nucleic acids (DNA and RNA) that are hiding in every cell in your body... you guessed it, has carbon. You are aware that you breathe out carbon, in the form of Carbon Dioxide in the breaths you're taking as you read this. It also makes the diamonds some of us wear or the gasoline in our cars. This incredible element utterly incredible.
A little further down the periodic table is Calcium, atomic weight of 20 and making up roughly 1.5% of your weight. While most of us know that this element is one used in bone building, teeth and in a strong compound known as Hydroxyapatite. What you might not know about calcium is that your body uses it during muscle contractions and the regulation of proteins! What's all the most fascinating about your body is that when systems that require calcium aren't functioning properly, your body will take the needed element from your bones and teeth, which can lead to osteoporosis! So make sure you're getting foods like milk, dark leafy greens (spinach, kale, collard greens) or yogurt in your diet.
We should not forget how these elements come together to do a job inside your body, but also, individually, have important functions. Some of these elements are also known as Cations and Anions. So let's start with one of the elements we are told to not ingest a lot of.
Sodium. Atomic number 11 on the periodic table and compromising roughly 0.15% of your body. Much like another element, Potassium (atomic number 19), sodium is a vital cation (a positively charged ion with fewer electrons than protons). Potassium also helps in the regulation of your heartbeat; each cell in your body requires potassium in order to function properly! (So make sure you eat the occasional banana!) Potassium, sodium and chlorine all allows for proper nerve transmission and muscle function. It's why Sodium Chloride (salt) and potassium are ingredients in things like sports drinks. Chlorine (atomic number 17) and also 0.15% of your body by weight, is an important anion (an anion has more electrons than protons, giving it a net negative charge). Not only does chlorine do the aforementioned things for your heart and nerves, it also used in the creation of hydrochloric acid; this is found in your stomach to digest food.
You also have many other elements in your body. Elements like Sulfur (atomic number 16), which are used in building proteins and in the use of metabolic processes like the utilization of fats and carbohydrates. Nitrogen (atomic number 7 and roughly 3% of your body weight) is vitally important in the creation of amino acids and proteins and most importantly, in the creation of Deoxyribonucleic acid (DNA) and Ribonucleic (RNA)! While you inhale and exhale nitrogen with each breath, your body gets the nitrogen it needs from the food you eat. You also have phosphorus (atomic number 15 and approximately 0.25% of your body weight) which helps keep bones and teeth strong as well as being in DNA and ATP (adenosine triphosphate), the energy molecule. You also have Magnesium (atomic number 12) in your body, which makes up roughly 0.005% of your body weight. Magnesium binds to ATP and is used by the body in the production of teeth and bones. But there are still others, in very trace levels, such as iron (in your blood), zinc, lead and copper. All of these are in such minute amounts but all important to your bodily functions.
It doesn't matter what element you are thinking about, if it is one of the 98 naturally-occurring, it came from a star that exploded like the Supernova in this image at right of the galaxy known as NGC 4526. The incredible heat and phenomenal pressure associated with these stellar detonations forces atoms to come together to make the very elements that are in your body and the device you're reading this on!
Without these explosions, we couldn't be here. No sun, no solar system, no humans, no pets, no plants, nothing. Stop and give a thought to the long-dead star that blew up so you can enjoy that coffee.