As I prepared to teach a lesson on vitamins and minerals for a college nutrition class, my mind went back to a pet guinea pig I had in high school. He was a happy little guy with the lettuce I fed him — until he got very sick one day. Soon after, I found him very dead.
It was then I learned that guinea pigs, like humans, cannot make vitamin C — a nutrient that quite literally keeps us knitted together. If we don’t routinely add this essential nutrient to our bodies, everything from our blood vessels to our bones eventually breaks down.
Most vitamins were discovered the same way I learned about guinea pigs… by accident. In the case of vitamin C, sailors of old who subsisted on long voyages without fresh foods soon succumbed to lost teeth, broken bones and bleeding disorders, a disease called scurvy. After centuries of trial and error, a British naval surgeon found that men provided with lemons and oranges on their sea journeys escaped this terrible fate.
And we’re still learning. We now know that vitamin C (ascorbic acid) is a powerful antioxidant; it protects our eyes from sun damage and helps prevent damage to our cells that can lead to cancer and heart disease. Recent studies now suggest that bodies replete with vitamin C tend to burn fat easier than those with low stores of this vitamin.
And yes, we do need vitamin C-rich foods daily, as our body does not store this precious compound. Besides citrus fruits, good sources include strawberries, tomatoes, kiwi, and red peppers.
Minerals are also a fascinating study. Our survival depends on the vast workings of at least 25 different elements from the earth. In the small balanced amounts we get in a healthful diet, minerals work to produce energy and vitality for our bodies.
At the same time, these nutrients for life can be toxic in large doses. Selenium, for example, works with vitamin E to protect our cells from damage and aging. But popping doses higher than 400 micrograms a day can make us very, very sick.
Nutrition scientists do not always come to the right conclusion about the workings of individual nutrients in food. What we do know for sure — especially in the study of vitamins and minerals — is that real food is the still the best way to get the most bang from our nutrient buck. More times than not, when researchers have attempted to show the benefit of one isolated nutrient on health, the results have been disappointing. Yet for decades, a mass of studies has conclusively shown the beneficial health effects of eating vitamin- and mineral-rich foods.
If only I’d known that for my guinea pig…
Barbara Quinn is a registered dietitian and certified diabetes educator affiliated with the Community Hospital of the Monterey Peninsula.