How often do we need to eat the various vitamins and minerals that are important to good health?
The latest recommendation from health officials in the US is for people to eat at least five servings of fruits and vegetables per day. If I eat ten servings one day and none the next, will my body know the difference?
A more specific example: I’ve heard it said that we can meet our need for vitamin D by exposing ourselves to sunlight for 30 minutes twice a week (it was’t clear whether total nudity was required, or just arms and face). This implies that vitamin D uptake, at least, need not be extremely regular.
What about others, like Vitamin C, calcium, iron, zinc, etc.?
Since no real nutritionists have answered yet, I know that scurvy (vitamin C deficiency) takes weeks to show up, so clearly vitamin C ingestion can be averaged over many days at least.
I presume most vitamins and minerals are similar. After all, you can go multiple days without eating anything at all without any real effects, other than maybe mood changes (assuming plenty of water, good health, etc. etc.)
There is a not-very-old thread about vitamins here.
The “five portions of fruit/veggies a day” rule is general from the anti-cancer society. Different vitamins, minerals etc. are stored for different length in the body - vitamin C can be stored for up to 2 years IIRC. But you don’t know how much you have stored up, how much you have eaten (content varies depending on many factors), or how much you use (if a cold is coming on, your immune system will use x times as much Vitamin C as on a normal day).
Oh, the Vitamin D rules are being re-written, the recommended dosage much higher than previous. I always hear at least 20 min. in the sun per day - but you have to factor in the latitude you’re at and the month (angle of the sun). One article even said that at the normal European latitude (more north than the US), for five months the sun’s angle is such that the UV waves necessary for Vitamin D production don’t reach us at all, so winter sun is useless. Using the calculator for my latitude, I would have to spend much more than 20 min. / day in the sun. And that presumes each day is cloudless and sunny - which it is not.
Seems you either get cancer from too much sun, but enough Vitamin D, or not enough Vitamin D to die of something else. With the new required levels of several thousands units, not even that fish oil that tastes terrible would cover the recommended daily dosis, so you practically have to eat pills.
I would imagine there would be a significant difference between water-soluble and fat-soluble vitamins, as far as how much irregularity in intake would be irrelevant to your body. Complicating matters is how nutrients interact with each other: calcium and vitamin D work together for uptake, for example.
I am curious about more general food intake - If I go a day without enough fruit or veggies can I make it up the next day or is that a waste of time? What about 2 days?
What do you mean by “general food intake”? Everything you eat is either reduced to caloric energy (carbohydrates, proteins*, fats and alcohol), passed through you (fiber), or absorbed as a nutrient (vitamins and minerals).
Your body needs a certain number of calories each day to function. Any calories consumed above that level is stored as fat, and if you don’t consume enough, fat is burned to make up the difference. Your liver and your muscles store a small amount of calories from one day to the next, but it is insignificant compared to your daily energy needs.
Vitamins and minerals, on the other hand, are stored for various lengths of time in your body, and that is what this thread is about. If you forgot to eat your “apple a day,” you don’t need to eat two the next day to stay alive. but if you skip your fruits and vegetables for weeks, you are going to have some deficiencies.
*Some proteins are required as a nutrient (essential amino acids), but the excess is used for energy.
The advice about daily fruits and vegetables isn’t designed to meet basic survival needs, but to ingrain (pun intended) good eating habits for the long run.
It’s just a variation of the old advice to have a balanced diet. Regular consumption of a balanced diet is almost guaranteed to give you the necessary supply of all nutrients in the long run.
Saying that you’ll skip your fruits and vegetables today because you’ll catch up tomorrow is a recipe for never catching up, because you’ll never really achieve that balance. Instead you’ll stick to less healthy foods that taste better. It’s certainly better if you do have more healthy stuff tomorrow, but the facts show that’s not the way most people function.
Think about it. If you actually needed to get every nutrient on a daily basis, the human race would have died out within a year. The natural environment doesn’t have a balanced diet available every day of every year, year after year. The world goes through seasons and years of feast and famine. Obviously, bodies have to be able to store nutrients and get along with less than optimal supplies over the short term.
At least in our household this fruit feast/famine cycle is quite present and sustainable. We go to the grocery store about every 2.5 weeks or so because we hate going so much. We buy a whole bunch of fruits and we usually eat them all within the first 2-5 days because either they start to go bad or we just like them a lot. The next 10-11 or so days we have no fruit.
An important point that is seldom brought up in such calculations is also skin color - darker skinned people definitely need more sun exposure to make as much vitamin D as lighter skinned people. People with dark skins at high latitudes have even more trouble with adequate vitamin D than the lighter skinned.
Yes, you can do that… but WILL you?
As someone else pointed out, it can become very easy to simply put off getting adequate fresh fruit/vegee consumption. You should try to eat some every day, and if for some reason you fall short no, it’s not a cause for worry, but it’s also a rare event.
Some people just don’t like to eat that way: they tend to go through phases where they eat a bunch of one thing for a while and then move on. If that’s the way someone likes to eat, it seems silly to force themselves into a different. less pleasant pattern when it really makes no difference in nutrition.
It may well be true for you. Every piece of evidence we have, however, says that it is not true for probably the majority of people in this country. If you’re only allowed to give a one sentence summary of what to do - and realistically, nuances are utterly ignored - which one should the government give?
It’s not true for me. And it may be the best advice for the government to give. But that doesn’t mean it’s the best advice to give on a message board in response to a specific question from a specific individual.
But nobody said it as a response to a specific individual. In fact, every person said that there is no need to eat nutrients daily. You’re creating an opposition that doesn’t exist.
I agree with** Exapno** - you’re seeing opposition where none exists. If you WILL “make up” for low fruit/vegee days (and yes, I’ve known people with eating habits like that) then it’s fine. The OP didn’t specify, though. If that person has been eating like that for years then I’d say don’t change but the average person tends not to do that.
Let’s put it a different way - during a typical month (let’s say 30 days) you should eat 150 servings of fruits and/or vegetables. It doesn’t matter how you divy them up - you can do 5 servings a day, 10 servings every other day, 15 every third day, whatever, 1 serving on Monday 10 on Tuesday 4 on Wednesday and so on and so on. What’s important is that over a month you get that many.
I read somewher that if you spread your nutritional needs out over the week, you’ll be fine; i.e. eating 35 servings of fruits and veggies one day; 42 servings of whole grain another day, etc. will do you.
I don’t know about your digestive tract, but if I ate “35 servings of fruits and veggies one day; 42 servings of whole grain another day” fine is the very last thing I would be. :eek: