How can I determine if my vitamin levels are appropriate?

Factual Questions
1

Mods: I am not asking for medical advice here, or looking for a debate on the effectiveness of vitamins.

Over the years, after talking to my doctors and reading up on vitamins and minerals, I have come up with a formula that works for me. I rarely get sick and my blood work always comes back fine. For example, from years of donating blood I learned that I am slightly anemic and now take an iron supplement. Since men are not supposed to take iron I talked to my doctor about it first and he agreed that it made sense for me. Since I started taking iron I haven’t seen a low blood iron level reading when I donate blood.

As a result of what I have learned I now take a popular men’s multivitamin along with some other supplements, like iron and Vitamin D3. You could argue that I could get by without taking vitamins or supplements and save some money, but I believe they provide me essential vitamins and elements I’m not getting from my diet.

Regardless of whether my diet is good enough to forgo vitamins, how do I know if my levels of trace elements and vitamins are where they should be? For example, I am taking a Vitamin D3 supplement since I don’t always go outside for 30 minutes a day and make my own. But is 2000 IU’s too much Vitamin D? Or too little?

Is there some kind of test I can ask for that would look for all of the normal levels of vitamins and minerals to ensure that I am taking enough of what I need but not too much of anything?

2

Why do you believe your diet is inadequate?

3

I’ve met very few people who had perfect diets. I don’t eat as many vegetables as I should and I probably eat too much red meat and fruit.

Taking a multivitamin daily ensures I get the micro-nutrients my body needs, but I think there can be problems with taking too much of a certain type of vitamin and mineral. I just want to take a test that tells me my Vitamin A or whatever level is within normal range based on what I am eating and what vitamins I am taking. I have to trust that the multivitamin is giving me the right amount, and I have no reason to believe it isn’t.

I think the human body will naturally excrete any excess water-based vitamins (like Vitamin C). But some vitamins cause problems if you take too much for long periods of time. I could just keep taking them and not worry about the levels, but that doesn’t seem prudent to me.

4

There may be some confusion here. Anemia involves having a deficiency in red blood cells or low hemoglobin (which carries oxygen in red blood cells). One potential cause of this condition is low iron. Donating blood according to the recommended schedule should not cause low iron, unless there are other factors involved (like poor diet or chronic blood loss from the G.I. tract).

Unless you have an unusually restricted or deficient diet, the evidence says otherwise.

*"In a blow to the multimillion pound dietary supplement industry, a review of 67 randomised trials of vitamin pills has found that far from prolonging life, they may actually shorten it.

There is “no convincing evidence” that antioxidant supplements cut the risk of dying prematurely and some of the commonest ones may increase the risk of early death, according to the review, published by The Cochrane Collaboration."*

There are tests to measure various vitamin/supplement levels, but they’re not routinely used and are both expensive and unnecessary in most people.

5

This. You don’t have to have some kind of super well-balanced perfect diet. The vast majority of people with even vaguely normal diets have normal levels of vitamins and minerals.

In the particular case of vitamin D, 2000 IU is rather a lot. However, the form you take is not the active form - your body converts it and that conversion is regulated by how much you need, so it may be the extra won’t do you much harm. In any case, the level of vitamin D that is best for you is still being fiercely debated.

6
7

Not necessarily. If you ingest something it could wind up in your toilet bowl, having never been absorbed.

8

Post hoc, ergo propter hoc.

You know because, barring vitamin or mineral deficiency arising from a very restricted diet, fairly serious metabolic disease, or very excessive vitamin consumption, your body regulates the amounts of vitamins it contains, and will break down and/or piss away the excess (normally there will be an excess, even without supplements).

9

I have wondered about D. I have been feeling very lethargic lately and my doc did a blood workup. Found out I was lacking vitamin D so he has me on 50,000 units weekly of vitamin D. Sounds like a lot to me, but I guess he knows what he is doing.

10

Cite?

Cite? 2000 IU is the amount you can absorb from direct sun exposure in 2-3 minutes. Not a lot.

No, D3 is the active form for humans.

11

The OP didn’t ask about antioxidant supplements.

12

He asked about how to find out if his levels of trace elements and vitamins were appropriate.

The study discussed in the article I linked to looked at “beta-carotene (a precursor of vitamin A that is converted into the vitamin in the body), vitamin A, vitamin C, vitamin E and selenium.”

Seems relevant to me.

13

This is a bit of a circular problem. Normal levels are almost always defined by comparison with the levels in the normal healthy population. In general this is going to include a wide variety of diets. I’m not going to spend hours searching for evidence that “normal people are normal”. There is evidence that the levels of vitamin D seen in general populations (especially those with limited access to the sun) are sub-optimal in terms of bone health, and shakier evidence that they may be sub-optimal for other health issues (MS, glucose control, prostate and bowel cancer to name a few). I’m not aware of much evidence that population levels are sub-optimal for other vitamins and trace elements. In fact as Jackmannii has said, in some cases high doses of vitamin supplementation have been shown to be harmful. Do you have any cites you want to share that give food evidence that an average, non-perfect diet results in suboptimal health for anything other than vitamin D?

The International Osteoporosis Foundation recommends 800 - 1000 IU/day in non-obese people (PDF). The UK National Institute for Clinical Excellence (PDF) states that there is evidence that 400 - 1000 IU/day may improve all-cause mortality, though noting that 2000 IU/day is recommended by some bodies. The US Insitute of Medicine recommends 600 IU/day, though it does give an upper limit of 4000 IU/day. 2000 IU/day is towards the upper end of the more generous recommendations and well above the more conservative ones.

In any case, if you are correct that one can make 2000 from only a few minutes sun exposure, then surely supplementation is futile in all but the most sun-deprived individuals?

D3 (cholecalciferol) is the form made in the skin by humans. D2 (ergocalciferol) is the form made by plants. Both D2 and D3 require hydroxylation at two positions to become the metabolically active form. Hydroxylation by the liver at the 25 position produces 25-OH-D2 or 25-OHD3 (calcidiol). This is not a controlled process and 25-OHD is the main form of vitamin D stored by the body (and the form measured in most blood tests). Hydroxylation by the kidney and white blood cells at the 1 position prduces 1,25-OHD3 or 1,25-OHD2 (calcitriol). The hydroxylation step is controlled by factors such as serum calcium, phosphate & parathyroid hormone levels. This is the metabolically active form, which (among other things) acts as a hormone to control calcium absorption. Wikipedia has a good summary.

14

http://boards.straightdope.com/sdmb/showpost.php?p=14143976&postcount=4

15

That first abstract mentioned in your link provides at best shaky grounds for assuming that a typical diet results in suboptimal health due to magnesium deficiency. It claims that substantial numbers of Americans consume less than the RDA for magnesium, which could be linked to abnormal levels of C-reactive protein, which could increase the risk of heart disease.

Magnesium does play a role in heart health, but it seems that deficiency is not that common.

“Although you may not get enough magnesium from your diet, it’ s rare to be truly deficient in magnesium.”

That link also makes it clear that magnesium supplementation is not a panacea for heart health, and in fact may be detrimental in some people.

As for Chris Masterjohn, whose conclusions on vitamin deficiency you approvingly cited in the link to your previous post, this is a person who’s affiliated with the Weston Price Foundation. Red flags immediately go up here, as Weston Price is a major source of health quackery and bad nutritional advice. Masterjohn says in your link that, contrary to what nutritionists and cardiologists tell us, cholesterol is not bad for your heart:

“In fact, while LDL, a major carrier of cholesterol in the blood, does have a role in heart disease, it is when poor metablism (sic), deficient diets, and toxins destroy the LDL particle that heart disease develops.”

That’s a conclusion straight from goofy-land. In particular, whenever some purported health guru starts going on about “toxins”, it’s time to ramp up the ol’ skepticism and keep a firm grip on your wallet. The “toxins” they warn about are virtually always nonexistent, have no significant effect on health, are metabolized normally in the body without consequence, or if they’re something to actually be concerned about, cannot be eliminated by whatever diet or supplement the guru is pushing.