The Skinny on Vitamin D Supplementation

Doc Alex, what is the big issue with Vitamin D and babies?
The main source of vitamin D for all humans is skin exposure to the sun’s UV rays (UV-B rays, specifically). The sunlight stimulates the skin to make active forms of vitamin D that are necessary for our bones and other bodily functions. Unfortunately, it is very hard to determine how much sunlight exposure is enough to make sufficient amounts of vitamin D, especially in small children.  Furthermore, we now know the dangers of direct exposure to UV light without the protection of sunscreen or clothing and to keep our infants under 6 months of age out of direct sunlight. This is great for the prevention of various skin cancers but is not good news for our production of vitamin D.  Breastfed babies and infants with darker skin color are particularly susceptible to a condition known as rickets, or extreme vitamin D deficiency. 

Why should we worry about Rickets?

Rickets is a dangerous condition because the extreme vitamin D deficiency occurs months before the appearance of any physical signs that a doctor could spot or which could be seen on an X-ray. Vitamin D deficiency may also first present itself in forms as serious as seizures, growth failure, lethargy, irritability or a predisposition to respiratory infections during infancy. Rickets also eventually causes the skull, rib cage and joints to enlarge, and causes curving of the spine and femurs (i.e. bowed legs).

Doc Alex, what should we do?  How should we prevent Rickets in our babies?
To prevent rickets and vitamin D deficiency in *healthy* infants, children and adolescents, The National Academy of Sciences Panel for Vitamin D recommends a supplement of 400IU/day, beginning in the first few days of life and continuing throughout childhood. Any breastfeeding infant, regardless of whether he/she is being supplemented with formula, should be supplemented with 400 IU of vitamin D.

Does this mean formula-fed infants are safe from developing a vitamin D deficiency?
All infant formulas sold in the United States have at least 400 IU/L of vitamin D. Since most formula-fed infants eat nearly 1L or 1 quart of formula per day after the first month of life, they will get the necessary amount of vitamin D in their diet. Any infant who regularly eats less than 1L or 1 quart of formula per day can get the recommended amount of vitamin D through vitamin supplements.

The required amount of daily vitamin D can be found in many liquid multi-vitamin supplements as well as in new vitamin D-only preparations. These vitamin D-only supplements are particularly good for a breastfed infant who has no need for multi-vitamin supplements.  As infants are weaned from breast milk and/or formula, vitamin D-fortified milk is recommended to provide 400 IU of vitamin D per day, however is not recommended to give cow’s milk until after 12 months of age (use the vitamin supplements to get the needed vitamin D before that time).  Also, adolescents who do not obtain 400 IU of vitamin D per day through vitamin D-fortified milk and vitamin D-fortified foods (like fortified cereals and egg yolks) should receive a vitamin D supplement of 400 IU/day.

Doc Alex, to wrap up, what is your “take” on vitamin D supplementation?
Parents in previous generations did not give their children vitamin D supplements and most of us “did just fine,” but we now know the risks of getting unprotected sunlight exposure (which is, unfortunately, the only kind that generates vitamin D!) and so parents are tending to avoid UV rays to protect their children from skin cancer and, simultaneously, are putting them at risk for rickets. Rather than “picking your poison,” just have your children wear sunscreen AND take vitamin D supplements and enjoy the best of both worlds!