The ABCs of Vitamins
Vitamins are natural components of foods and necessary for normal physiologic functioning. One of the most critical responsibilities of vitamins is their role as co-factors for enzymes.
While vitamins are essential, unlike macronutrients, they don’t function as direct energy sources.
The general categories of vitamins include fat-soluble and water-soluble, depending on whether they dissolve well in either fat or water, respectively.
Vitamins A, D, E, and K are classified as fat-soluble. These are mostly absorbed passively in the GI tract, and usually must be transported bound to dietary fat.
In the body, fat-soluble vitamins are usually found in the portion of the cell, which contains fat, including cell membranes, lipid droplets, etc.
These vitamins are typically excreted through our feces.
Due to the unique storage capacity of fat-soluble vitamins, it’s not necessary to consume them every day.
B vitamins and vitamin C are water-soluble. These vitamins are absorbed both by passive and active mechanisms in the gastrointestinal tract. They rely on carrier proteins for transport.
Since body water is always being turned over, water-soluble vitamins are not stored in large amounts in the body; they’re typically excreted in the urine along with their breakdown products. And for this reason, it’s important to get them on a daily or weekly basis.
Also interesting to note is that water-soluble vitamins can also be lost in water during cooking and storage. Which means the best methods to preserve vitamins include steaming, sauteing, roasting, and microwaving. That’s why boiling in water, and then discarding the water, will likely result in loss of some vitamins.
Remember that frozen and canned vegetables and fruits were harvested and then immediately preserved, so unless they are boiled after opening, they are likely to have a high nutrient content.
Vitamins are not a one-size-fits-all situation. Many factors determine our needs, including gender, GI health, medication use, stress, exercise, and age-related changes.
All About Minerals
Like vitamins, minerals are not direct sources of energy, yet are still considered essential in the human diet. They serve as building blocks for body structures: they form the foundation of teeth and bones, and help to construct other cells and enzymes.
Minerals are already in the simplest form possible, they are elements, so the body doesn’t need to break them down before absorption. Further, minerals won’t be degraded on exposure to heat, so minerals in food stay unharmed during storage and cooking.
The minerals in foods come from the environment, such as soil and water taken up into plants during the growing process, and then incorporated into the animals that eat the plants. Whether humans eat the plant directly or the animal product, all of the minerals in the food supply originate from Mother Nature.
Minerals can act as co-factors in enzymatic reactions or as enzymes themselves. Minerals can also act as electrolytes that maintain the electrochemical gradient across the cells of our bodies.
Other molecules found in food, such as phytates and oxalates, can alter one’s ability to absorb minerals. This only becomes an issue for those whose intake is limited to just a handful of foods that are high in these compounds (e.g. cultures eating only rice or corn, etc.). In the context of a mixed diet, with a variety of whole foods, they are unlikely to pose an issue.
It’s also important to note that if someone buys a certain vitamin or mineral at the store to replace a vitamin or mineral they are missing out on from food, it’s not quite the same thing.
The micronutrients in whole foods are a package deal. They come with other compounds that work together, creating a cascade response in the body. It’s hard to duplicate that with an isolated supplement.
Phytonutrients
Like vitamins and minerals, phytonutrients - nutrients found in plants - don’t directly provide energy to the body. Yet they do offer a variety of health benefits.
Of course, while scientists are continually discovering “new” phytonutrients (there are over 10,000 already identified), it’s important to remember that these discoveries simply mean that someone isolated the nutrient in a lab and named it. In other words, that nutrient has always been part of the plant.
Bottom line: Eating plants is good. Not only because of the nutrients we know about. But because of the ones we don’t yet know about.
Phytonutrients not only give plants color, they indicate which disease-fighting nutrients are inside. And deficiencies in phytonutrient intake might increase the risk of various chronic diseases.
One report indicated that 31% of folks don’t get enough greens, 22% don’t get enough reds, 21% don’t get enough yellows and oranges, 14% don’t get enough whites, and 12% don’t get enough purples and blues.
Some phytonutrients are so powerful that they can influence our response to the world around us.
For example, naringenin in grapefruit, influences how we metabolize drugs. Raspberry seed oil has a sun protection factor. And garlic may have a blood thinning effect.
Phytonutrients work through various mechanisms, including:
- functioning as antioxidants
- influencing hormonal function
- protecting DNA from carcinogens
- anti-bacterial and anti-viral properties
- reducing inflammation
- influence blood coagulation
- inhibiting fat synthesis
And while phytonutrients sound appealing, they can work in complex ways.
For example, some work by mildly stressing cells in the body, ultimately making them stronger by building internal defense mechanisms (this is called hormesis).
