Vitamin supplements

U.S. consumers spend over $12 billion on vitamin and mineral supplements each year.  Over one-third of Americans are taking a daily supplemental multivitamin.  Though there are several health conditions that necessitate vitamin supplementation, many people take supplements in hopes of preventing chronic diseases, or boosting energy and immunity. 

Oftentimes it is the notion that “if a little bit of something is good, then a lot is even better.”  However, this may not the case.   

Vitamins are organic compounds that our bodies need to function properly (“vital”-mins).  Our bodies cannot produce vitamins in sufficient quantities to meet the need.  Therefore, vitamins must be obtained through our diet.  

In general, vitamins and minerals are used by the body to carry out chemical reactions.  They are critical cofactors to enzymes in the machines of our cells.  Without them our cells cannot produce the essential structural products that keep us together nor carry out the cell metabolism that keeps us going.

The 13 vitamins are grouped in two main classes: water-soluble vitamins and fat-soluble vitamins.  The fat-soluble vitamins are vitamins A, D, E, and K.  The water-soluble vitamins are the eight B vitamins and vitamin C.  Water-soluble vitamins easily dissolve in water.  Therefore, they are more readily excreted through the urinary system and are not stored in the body in large quantities.  

Fat-soluble vitamins do not dissolve well in water.  They must be absorbed from the intestines with the help of fat in the diet.  These vitamins are more easily stored in the body and, as a result, are more likely to over-accumulate and this can lead to hypervitaminosis.  

The health consequences of certain vitamin and mineral deficiencies are well-known.  In most circumstances, diseases such as rickets (vitamin D deficiency), scurvy (vitamin C deficiency), and beriberi (thiamine or B1 deficiency) occur in select populations where nutritional intake is less than adequate.  Other deficiencies can be caused by the inability to absorb a vitamin or mineral, such as pernicious anemia (vitamin B12 deficiency) or iron deficiency anemia.  These are a few of the medical conditions wherein supplements are recommended.  

The big question is whether taking extra vitamins and/or mineral supplements is helpful to individuals who are otherwise well-nourished.  In other words, do these supplements help to lower one’s risk of developing cardiovascular disease, cancers, dementia, and other chronic diseases?     

The answer can be summed up by a quote from an editorial written in the Annals of Internal Medicine by one of the co-authors of a recent study examining this question.  

“Although available evidence does not rule out small benefits or harms or large benefits or harms in a small subgroup of the population, we believe that the case is closed. 

Supplementing the diet of well-nourished adults with mineral or vitamin supplements has no clear benefit and might even be harmful.  These vitamins should not be used for chronic disease prevention.”             

The content in this column is for informational purposes only.  Consult your physician for appropriate individual treatment.  Dr. Reynolds practices Family Medicine in Chesterfield.

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