Eat, Drink, and Be Healthy by Walter Willett & P.J. Skerrett

Author:Walter Willett & P.J. Skerrett
Language: eng
Format: epub
Publisher: Free Press

CHAPTER ELEVEN

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Take a Multivitamin for Insurance

VITAMINS WERE ONCE THOUGHT OF as nutrients needed in small amounts to prevent diseases with exotic-sounding names like beriberi, pellagra, scurvy, and rickets. Early nutritional guidelines for vitamins focused on the amount needed to avoid these diseases. As they became rarer and rarer during the twentieth century, it seemed that the vast majority of Americans were getting enough vitamins. Getting more than the amounts needed to prevent these so-called deficiency diseases, so the thinking went, was a waste. Or, as a colleague of mine once wrote, vitamin supplements may not do much other than give Americans the “richest urine in the world.”1

Some innovative thinking and the wonderful, logical conversation of science has been changing the way we think about vitamins, minerals, and other micronutrients. The biggest shift has been the realization that many chronic diseases, such as heart disease and some cancers, could be partly due to nutrient deficiencies, just like beriberi and scurvy. New findings suggest that some people—probably many people—don’t get enough of these essential micronutrients. By increasing the amount we get, mostly from food but maybe from supplements as well, we can substantially improve our long-term health.

What blew the cover off the old vitamin-deficiency-disease connection was the discovery of a direct link between inadequate intake of the B vitamin folate (also called folic acid) and birth defects such as spina bifida and anencephaly. Both of these, collectively called neural tube defects, happen when the tissues destined to become the spinal cord, the bony tube that protects it, and the brain don’t develop as they should during the first twenty-eight days of pregnancy. Spina bifida can cause paralysis and other disabilities. Children with anencephaly are born without most of the brain and spinal cord; they are either stillborn or survive for only a short time after birth. Worldwide, about 300,000 babies are born with neural tube defects each year.

Neural tube defects were most common in poor populations with poor diets. That connection prompted a search for nutritional causes. In 1976, a British team found that mothers of children with neural tube defects had relatively low levels of micronutrients.2 Other teams discovered that drugs that interfered with folic acid also increased the risk of having a child with a neural tube defect. The not-uncommon scientific seesaw followed: some studies implicated low folic acid in these birth defects, others didn’t; some small trials showed a benefit for folic acid supplements, while others didn’t. In the end, two large trials gathered conclusive proof that women who didn’t get enough folic acid were much more likely to have a child with spina bifida or anencephaly, and that taking folic acid supplements could prevent about 70 percent of these birth defects.3 This was truly a remarkable achievement for a simple and cheap vitamin pill.

At first, the recommendations on folic acid were cautious. Initial guidelines from the Centers for Disease Control (CDC) in 1991 were aimed only at women who had already had a child with a neural tube defect.

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