Vitamin D is essential for good health but as many as 90% of African Americans are deficient in this important nutrient. To restore Vitamin D to normal level, researchers determined that big doses may be necessary for up to a year.
While Vitamin D can be produced in the skin on exposure to UVB radiation, African Americans are at a greater risk for deficiency because having darker skin limits a person’s ability to produce vitamin D. And living in some northern countries can exacerbate the problem as sunshine is weak during long winter months such that the body makes little or no vitamin D.
Restoring Vitamin D
To study the feasibility and efficacy of Vitamin D supplementation to eliminate Vitamin D deficiency, researchers from the Medical University of South Carolina recruited 47 African American and white men to receive 4,000 IU of Vitamin D3 for one year.
At the start of the study over 90% of African Americans had deficient levels and 66% had very low levels of the non-active, “storage” form of vitamin D (25- hydroxyvitamin D (25(OH)D) in their blood. The baseline levels of the same form of vitamin D in white study participants were significantly higher at the start of the study.
By the end of the study, 4000 IU daily eliminated any significant differences in circulating concentrations of 25(OH)D between African American and white men.
Nutritional Role of Vitamin D
Vitamin D is necessary for many of your body’s structures and functions including:
- Promoting calcium absorption for building strong bones and teeth
- Supporting your immune system
- Supporting muscles and other tissues
- Promoting normal cell and tissue development
Food Sources of Vitamin D
Vitamin D is found naturally in very few foods: some fatty fish (mackerel, salmon, sardines), fish liver oils, and eggs from hens that have been fed vitamin D.
In the U.S., milk and infant formula are fortified with vitamin D so that they contain 400 IU (10 mcg) per quart. However, other dairy products, such as cheese and yogurt, are not always fortified with vitamin D. Some cereals and breads are also fortified with vitamin D as well as some beverages such as orange juice.
Despite our body’s ability to make vitamin D from sunshine or obtain it through some foods, studies indicate that more than 70% of the US population may be deficient. We explore why in a previous post: Most Americans Don’t get Enough Vitamin D…Do You?