Most people today are aware of the need of vitamin D as an essential vitamin. It is necessary in the support of basic structure and function of our cells and more specifically it is needed for the absorption of calcium and phosphorus. A deficiency of vitamin D can lead to Rickets, Osteoporosis and Osteomalacia. While some foods are already fortified with Vitamin D, and many people take dietary supplements, it has been questioned if we are getting enough.
An article published in the Journal of the American Nutraceutical Association reported on new research suggesting that many people are deficient in this vital nutrient. One study conducted at the University of Pittsburgh Schools of Health Sciences found that 92.4% of African-American newborns and 66.1% of white babies had insufficient vitamin D levels at birth. The study also found that more than 80% of the African-American participants and nearly half of the white women tested had levels of vitamin D, at the time of delivery, that were too low despite the fact that over 90% of them had been taking prenatal vitamins during pregnancy.
Dr. Robert Heaney, a professor at Creighton University School of Medicine, has been conducting research on vitamin D for nearly two decades. He stated, "The amount of vitamin D in supplements isn’t nearly enough," and went on to say "The principal obstacle has been we haven’t known how much vitamin D we have needed until the past two years.
Current estimates from Dr. Haney’s research estimate that the body uses 4,000 IU, per day, of vitamin D. The current dietary reference intake for women up to age 50 is 200 IU per day. As for the concern of safety regarding Vitamin D, Dr. Haney’s research has shown that vitamin D safety does not become an issue until a person exceeds well beyond 10,000 IU per day.
In diet, vitamin D is found in liver, fish, butter, milk, egg yolk, yeasts and some mushrooms. However there is some question as to whether modern agricultural practices have resulted in these foods providing less vitamin D than the same foods produced only decades ago. The human body also has the capacity to convert cholesterol into vitamin D when the skin is exposed to sunlight. People with lighter skin will produce more vitamin D from sunlight exposure than those with darker skin. Again modern lifestyle changes may not result in anyone having as much regular, full-body exposure to sunlight as experienced by their ancestors.
Ultimately a diet rich in whole foods, safe exposure to natural sunlight and appropriate use of dietary supplementation may be used together to ensure that this essential vitamin is available to do its part in supporting optimal health.