I am generally skeptical of any claim (made by EITHER the alternative or modern medical camps) that Americans are deficient in any particular vitamin or nutrient. “Americans are not eating enough X,” the headlines cry! It just does not seem logical to me that in this day in age, where obesity has become an epidemic, that Americans are not ingesting enough of anything! But the up and down claims about vitamins are enough to send any rational consumer into a tailspin of confusion. One day we need to double our consumption of a particular nutrient, the next day we are told that too much of said nutrient is harmful then we are told that we weren’t deficient in the first place! This is the roller-coaster story of vitamin D.
Because the skin produces vitamin D when exposed to sunlight, it was thought to be common wisdom that anyone living in northern latitudes would need an extra boost of dietary vitamin D. Studies done like this one on adolescent girls living in Maine (my home state) demonstrate that vitamin D levels drop in the wintertime. But there has been a lot of discussion about what constitutes vitamin D deficiency and insufficiency. A recent consensus study conducted by the Institute of Medicine’s Food and Nutrition Board panel concluded that the population of Americans and Canadians studied do not display dietary deficiencies of vitamin D, even at northern latitudes, largely because so much of our food is fortified. They also concluded that the early recommendations for vitamin D increase were largely inflated, and the 600 international units is sufficient for most age groups (popular press has covered these results).
The Institute of Medicine experts worry that taking vitamin D in large doses over a long period might harm some people. The evidence is inconclusive, but the panel points to studies hinting at higher levels of pancreatic and esophageal cancer. Panelists say there’s reason to worry about excess deposits of calcium in arteries from too much vitamin D.
Dr. Michael Holick of Boston University, who discovered the active form of vitamin D 40 years ago and is a leading proponent of high doses, isn’t backing away from his conviction that most people need at least 3,000 units a day. That’s what he takes, and what he recommends to his patients. Sometimes he prescribes 50,000 units of vitamin D a week.
Here is the crux of the argument I make when any “eat more of X” claims crops up in conversation:
American’s have an incredibly versatile diet. Very few of us eat the same thing for every meal, and in fact most of us have enormous variety in our weekly diets. Contrast that to the diet of a carnivore living on the savannah in Africa. Monday: antelope, Tuesday: crickets, Wednesday: antelope, Thursday: half-eaten antelope, Friday: zebra. Not a lot of variety there, and yet carnivores have been around and propagating longer than us omnivores. Our dietary versatility means that it is less likely that our diet will be completely lacking in any particular nutrient. However, I want to point out that you could eat nothing but Corn Pops with chocolate milk and it would only take a few bowls to meet your daily vitamin D requirement.
Added to Point 1 is the fact that Americans are terrible at portion control. When was the last time you only ate the 5.5 chips that the package says is a single serving size? Did you know that many Red Delicious apples are larger than a single serving of fruit? Do you make your omelets with medium sized eggs or Grade A Extra Large? We are a well-fed nation, to the point that obesity is becoming more of a problem than starvation (Google “Hunger Paradox, it is fascinating). The likelihood that we are not eating enough of anything is pretty laughable.
Of course there are certain populations that truly may need extra doses of vitamins. Pregnant women, athletes, anyone who burns way more calories than they easily take in may have trouble maintaining vitamin levels. But for the large majority of the computer tapping, TV watching masses, I favor the age old adage, “’EVERYTHING IN MODERATION.” Do not eat a lot of anything in particular, do not eat too little of anything, and you are likely to maintain that nutritional sweet spot for your whole life. If you eat only fast-food hamburgers for every meal of every day, you may run into problems, throw in a bowl of Corn Pops with chocolate milk every once in a while.