There is very little doubt that if we eat the diet we were designed to eat and spend adequate time in the sun that we will get most if not all the nutrients we need. That’s the ideal, but not the reality for a lot of us. I was recently advised by a group of physicians who are experts in the area that it is reasonable, and probably preferable, for adults to take a low dose multi-vitamin, 1000 units of Vitamin D and 1000 mg of fish oil every day. I’m certainly not an expert, so you may want to take the following with a grain of salt, but here’s my take on this advice.
Only 3-4% of Americans reach the DGA (Dietary Guidelines for Americans). The ADA (American Dietetic Association) conclusions on the subject of multivitamins are basically a) it’s always preferable to get your vitamins from real food and b) given that it doesn’t happen for most people, multi-vitamins can bridge this nutrient gap. (Marra MV, Boyar AP, J Am Det Assoc 109:2073, 2009) Don’t fool yourself into thinking that taking a vitamin makes up for not eating right – your best bet is still the marvelous combination of vitamins and minerals found in plant foods.
The NIH consensus statement from 2006 on the subject of multivitamin/mineral supplements (MVMs) states “the present evidence is insufficient to recommend either for or against the use of MVMs by the American public to prevent chronic disease.”
Where does it leave us? As Michael Pollan sums it up, the best strategy is to “Eat food, not too much, mostly plants”. It’s clear that it’s stupid to take high dose multivitamins because of the potential side effects. (unless you are treating a known deficit). On the other hand, a normal (low) dose multivitamin is probably reasonable to help bridge some nutrient gaps – even though there are no conclusive data that say it will make a difference in preventing disease.
If you google “Vitamin D” you get over 13 million hits. A PubMed search gives you over 49,000 references. Anyone in medicine (and everyone else as well) has learned by now that Vitamin D is a big deal. It’s looking more and more like most of us are vitamin D deficient and that being deficient in Vitamin D is bad for you. http://www.vitamindcouncil.org/
The bottom line on this one is that you need to talk to your own doctor (and, yes, you should have one!) about checking your Vitamin D level. 30ng/ml is minimum, but some physicians feel that levels should be kept over 50 or 60ng/ml to optimally decrease the risk of some cancers and other pathologies. 1000IU is probably going to be the new recommended daily dose in the United States. This one seems pretty straight forward: a) get your level checked and b) it’s ok to take 1000IU per day.
Fish oil is a concentrated source of omega 3 fatty acids i.e. eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Most Western diets are heavy in omega-6 fatty acids, which decreases the ratio of omega-3 to omega-6 fatty acid. It’s this change in ratio that is thought to increase the inflammatory response. Supplementing your diet with omega-3 fatty acids changes the balance back to a more favorable (less inflammatory) ratio. There are good data that achieving this favorable balance in omega-3:omega-6 fatty acids can help prevent (and even treat) cardiovascular disease and may be beneficial in a variety of other inflammatory diseases as well.
So, it makes sense to work on changing this ratio by increasing your omega-3 fatty acid intake. You can do this by eating around 12 ounces of oily fish (sardines, mackeral, salmon) a week, which is the best option if it’s possible. For some people that’s not realistic, so the supplement may be a reasonable alternative. There is one caveat – fish oil supplements can be contaminated, so it’s worth knowing the company (and not just buying the cheapest brand). Other than the risk of contaminants, there’s not much downside to taking fish oil in a reasonable amount. 1000 mg a day (on days you don’t eat fish) is what is usually recommended.
Great review, Mary!
It reminded me of David McCandless’ “Information is Beautiful” website ( http://www.informationisbeautiful.net/visualizations/snake-oil-supplements/ ), with an astoundingly engaging bubble-chart showing the level of evidence for and against all the different nutritional supplements tested to date.
Just thought I’d say that ground flaxseed is an excellent way to get your omega 3’s and it comes without the contaminant and environmental perils of fish oil! It can easily be spread on oatmeal or cereal every day…