Having said that, we have a lot to talk about this time around, because the "other" category of nutrition is actually pretty complex. As you might imagine the body uses a ton of different elements in its construction and you can't just take in pure forms of the elements (generally) in order to achieve growth and function.
The first thing we have to talk about is vitamins. There are, if I remember correctly, 13 vitamins. These aren't 13 individual chemicals but actually 13 categories into which chemicals called vitamers are sorted depending on biological activity. 4 of the vitamins are soluble in fat which is one of the reasons why a fat-free diet won't work and the other 9 are soluble in water which is why we have to consume so much of it.
As something of an aside, you are basically hydrated if your urine is very pale or clear. The usual rules of thumb for how many glasses of water a day to drink vary as widely as how many calories a day to consume and so I will refrain from posting any guidelines apart from that metric.
Now, your 13 vitamins are A, B1, B2, B3, B6, B7, B9, B12, C, D, E and K. For each vitamin there is a maximum and minimum daily intake guideline, an associated underdose and overdose syndrome, and different food sources. As a general rule unless you are otherwise unhealthy or for some reason cannot physically eat enough food to obtain each of the vitamins or for some strange reason do not have access or are allergic to whole categories of foods you should not need to supplement your vitamin intake. As a matter of fact, Vitamin D can by synthesized by your body under UVB exposure.
The different vitamins all have different effects on the body and prioritizing them, say, to achieve a particular effect over what you would achieve by consuming merely the daily requirement may be one vector by which you can tune your diet to tune your body. For example, I tend to supplement vitamin E in winter and take more foods with vitamin E in the rest of the seasons because it plays a role in regulating mood, and there is a seasonal component to my otherwise regular up-down cycle of biploarity.
In addition to some vitamins being soluble in fat and some being soluble in water, all of the vitamins are affected by cooking and different vitamins respond to different cooking methods in different ways. A fantastic table of these effects is found on wikipedia, but there's a few general rules of thumb: losses are greater for boiling than steaming and with the exception of B2 vitamins are more available to the body in the raw food than after cooking.
Having said that, this isn't an argument that all diets should be raw food diets any more than my personal preference in tuna preparation is that all tuna dishes should be nigirizushi.
After your vitamins come your minerals, which can be divided into two categories based basically upon bodily need, your macrominerals and your trace elements. For the vast majority of these elements, your body really wants the ions. Fortunately, ionization happens readily in aqueous solution and your body is 70% water for the ions to be dissolved into so we've got that part covered. Excess minerals are among the excreted substances in urine which a humorous person could suppose would allow you to call your urinary tract an ion cannon but I personally think we're above bathroom humour here.
Your macrominerals are: calcium (important for bone health), Chlorine (more specifically, chloride ions), Magnesium (which is particular important as Magnesium is a key component of ATP which is the chemical that transfers energy around your body); Phosphorous (in ATP, DNA, and Bones); Potassium (regulating electrolyte balance), Sodium (which your body needs because it is used in muscle control which is kind of important for things like having a heart-rate and, you know, doing things); and Sulfur, which is a component of pretty much all of the amino acids both essential and otherwise.
Now, you can overconsume the macro-minerals and sodium over-consumption is particularly problematic which is why it's one of those nasty words and why you're seeing so many processed foods bragging about low sodium content. If you're otherwise healthy, however, there's no good reason to remove it from your diet completely, but you may want to stay below about 2.5 grams per day which is quite a bit more than you need but still below the range where it causes hypertension.
After that come the trace elements which are all essential, mostly because your body can't produce elements from lighter elements - as cool as your body is, it doesn't really work with nuclear chemistry that often. We need cobalt, copper, chromium, iodine, iron, manganese, molybendum, selenium, zinc, and maybe vanadium (we haven't decided that one yet).
Now, of those I would suggest that they are all important but particularly iodine (which most people only obtain through iodized table salt now that we aren't so big on the organ meats) as it prevents glandular dysfunctions, iron as it moves oxygen around the body, chromium which allows your body to process sugars, and manganese which lets your body actually do things with the oxygen its moving around are the most important, but again, you need all of them. Trace minerals are the ones most often low on the diet so I strongly recommend investigating your consumption and then supplementing the ones you're lacking if necessary.
That's All, Right?
Well, no, not really. There are some other dietary components that aren't as established in the zeitgeist but nonetheless are becoming increasingly important in our understanding of human nutrition.
Antioxidants which either prevent the formation of free radicals during metabolism or absorb them all up (thereby preventing cell damage) are becoming increasingly popular in recent years. I've spoken about them before here in my tea reviews and while I don't pay the most attention to them I've learned that they have been clinically demonstrated to have some good health effects, though clinical trials have shown them to be minor and that over-supplementation can be harmful. Your body can actually produce quite a few of these compounds on its own with enough the the precursors Glutathione and Vitamin C. There are thousands of different antioxidant compounds of dietary relevance and tracking your consumption is largely impossible based just on that complexity, but it should be noted that variety in foods that are rich in antioxidants like colourful fruits and vegetables is better than an antioxidant pill.
One subgroup of about 4,000 antioxidants are the phytochemicals (like the polyphenols) which are, like antioxidants in general, sufficiently complicated that no one phytochemical can be said to be preferred by the body over any other. In point of fact there's some evidence to suggest that useful phytochemical intake comes only from diet and that supplementation is essential a waste of money with zero clinical benefit. Antioxidants and Phytochemicals are the bleeding edge of nutritional science and we really don't know much about it but this is where the developments will be coming from.
The last thing I want to talk about is the stuff that is living inside of you. Believe it or not not everything we eat is dead and nor should it be. Your GI tract in particular is practically a nation of different species of organisms from Lactobaccilicus to E coli, all of which are necessary for a happy, healthy you. The exact species and proportions are being studied and do vary according to age, but there are circumstances in which getting more - by eating live-culture foods like yogurt or by supplementation - is advisable, such as after courses of antibiotics. Dietary Fiber also plays a role in the health of your gut flora which then goes on to regulate certain other aspects of your life such as how much of your time you waste playing angry birds on your phone in the john.
For the record, I hate angry birds.
For the record, I hate angry birds.
Gut Flora, as it's called, performs a number of functions for you. Complex carbohydrates are broken down into more managable forms by fermentation, which reduces the amount of food you have to eat to reach a caloric break-even point and also produces that other uncomfrotable waste produce - flatulence.
There's some evidence that some of the species of Gut Flora, which use your GI Tract's mucus lining as their growth substrate, actively protect that lining and even prevent certain forms of injury to that lining from forming, which would otherwise be very painful.
Furthermore, because your body has a colony of bacteria already inside of it that's eating up all the things bacteria like to eat up, the gut flora have a competative advantage over pathogenic bacteria that would otherwise make you sick. This is not unlike the way that a well-planted fish tank is less susceptible to algae blooms, in fact, it works on the very same mechanism. In fact, maintaining a healthy internal ecosystem can be so useful that it can even prevent or help to control irritable bowel syndrome.
So while, yes, some strains and species of bacteria are harmful to you, so are some varieties of virtually everything else. If anything over the last few weeks we've learned that there are no good foods or bad foods, only better foods and worse foods. Even the worse foods aren't really verboten. Your body doesn't actually acknowledge the human compartmentalization of time and even circadian patterns of sleep and eating are mutable as we're going to see in a few posts when I talk about polyphasic sleep. While large swings in nutrition are ill-advisable as anyone whose gone from one type of diet to another can probably tell you, diversions from your diet on occasion won't actually hurt you as badly as some people believe, and on a psychological level would probably do you some good.
I mean, of the four major human experiences - death, food, sex and other humans, only death is more ubiquitous than eating. By our very nature we are obsessed with and concerned with only eating enough not only to survive but to reproduce. And while I can and others have survived very well on diets made entirely of single-flavour elements such as the Great American Meat and Potatoes paradigm or the relatively new Soylent Smoothie synthetic diet, the happiest people I know are all the ones who eat the most differently. The human brain is, after all, thirsty for experience, and whether we crave variety in having scalloped potatos this week instead of mashed or always having some kind of cake for dessert on sunday dinner or it's bouncing from sushi to pasta to brioche to burgers to salads over the run of a weekend, variety is the cliched seasoning of life and, what's more, we've just seen that there's nutritional benefits to it as well.