August 8, 2007

You Ask, I Answer: Multivitamins

What is your response to Dr. Willett, who suggests a multi-vitamin as an inexpensive form of insurance in his book Eat Drink & Be Healthy? My understanding is that a multi-vitamin is a good idea regardless of diet since aside from providing the daily minimum amounts of vitamins it also provides certain things like minerals which even for a smart eater can sometimes be overlooked?

-- Guy Betterbid
New York, NY

For those of you who don't know, Dr. Walter Willett is a professor of Epidemiology and Nutrition at Harvard's School of Public Health as well as Professor of Medicine at Harvard Medical School.

A renowned medical researcher, Dr. Willett is perhaps most famous for his revised dietary pyramid, which places exercise and weight management at the base, plant oils and whole grains on the second level, and red meat, butter, and refined grains as neighbors at the tip.

Along the side, Willett borrows from the Mediterranean food pyramid by including alcohol (in moderation) but then adds his own touch by including multi-vitamin supplements.

I'm not quite as gung-ho as Dr. Willett on the thought of people popping a Centrum once a day.

First off, there is so much fortification in today's food that getting most vitamins and minerals is not too difficult. Even the sweetest and least nutritious of children's cereals provides 100% of many of these nutrients.

On top of that, we have beverages -- such as Vitamin Water and even Diet Coke Plus -- as well as "energy bars" that also throw in a day's worth of vitamins and minerals.

It's crucial to realize that it does not take extreme amounts of food to get a daily supply of certain vitamins and minerals. As I recently posted, just half a cup of red peppers provides 100% of our vitamin C needs.

Meanwhile, half a cup of baby carrots provides 300% of our vitamin A requirements, one cup of raw spinach packs in 181% of the Vitamin K we need each day, and a sandwich made with two slices of whole wheat bread contains 60% of our daily manganese needs.

It is true that the recommended intakes for minerals like calcium, potassium, and magnesium are only achieved by having a combination of foods rich in them.

That being said, I believe it is important to recommend people get as much of their vitamins and minerals from real food as possible.

When you eat a carrot, you aren't just getting Vitamin A. You are also getting fiber, phytonutrients, carotenoids, and antioxidants that are not available in pill form.

Additionally, increasing dietary potassium often correlates with a reduction in sodium intake. That's two birds killed with one stone if vitamin and mineral consumption is first tackled via diet.

I also believe that relying on supplements tends to give people false security, thinking that popping a multi-vitamin in the morning is a free pass for going through the rest of the day without paying attention to the food they are eating.

I think it is much wiser to take a look at what vitamins and minerals one tends to be deficient in and then tackle that problem specifically (ideally by altering one's diet first).

Vitamin D is not readily available in many foods (and most people in the world do not get enough from the sun during winter months), so I do not see anything wrong with supplementation. I also think calcium supplementation is important if the diet does not provide sufficient coverage.

Additionally, people on restricted diets often need to supplement their diets appropriately (i.e.: vegans and vitamin B12).

While we're at it, I would like to clarify that vitamins do NOT provide energy. Calories provide energy. Vitamins do not contain calories.

Yes, the B vitamins are necessary for energy pathways to work properly, but they do not give a boost of energy in and of themselves.

Back to the original question: people eating balanced diets do not need to pop a multi-vitamin every day.

They are better off seeing what nutrients they are actually deficient of, see if they can get them by altering their diet, and, if that's not possible, look to supplement that specific vitamin or mineral by means of a pill.

1 comment:

Dirk Hanson said...

"people eating balanced diets do not need to pop a multi-vitamin every day."

I think that's true--which means that there are a lot of us who had better pop that multi-vit on a regular basis.

On the other hand, it is certainly possible to get too much of a good thing, as you suggest below in the post about Vitamin C.