Importance of Vitamin D for people with darker skin pigmentation

The body naturally produces vitamin D in response to the skin's exposure to sunlight. People with darker skin pigmentation, like African-Americans, are at greater risk for vitamin D deficiency or insufficiency because the higher presence of melanin reduces the body's ability to produce vitamin D.

The risk for deficiency in vitamin D is substantial among African Americans and other ethnic groups with dark complexions. The elderly, people with sedentary lifestyles, and those who regularly wear clothes that cover most of the body also have an elevated risk for vitamin D deficiency.

Vitamin D Deficiency and Type 2 Diabetes in African Americans: The Common Denominators

The prevalence of vitamin D deficiency and type 2 diabetes is disproportionately elevated in African Americans compared to other ethnic groups in the United States. Despite recent advances in diabetes treatment and management, the most significant escalation in incidence of type 2 diabetes has been in this group. 

Some studies suggest a possible role for vitamin D deficiency in the development of type 2 diabetes and that insulin secretion and insulin sensitivity are reduced when vitamin D levels are deficient.

Obesity, hyperglycemia, cardiovascular disease, and minority race are common among people with type 2 diabetes and vitamin D deficiency. These phenomena are known precursors to the development of type 2 diabetes and exacerbate the risk for complications where diabetes exists. 

Poverty, urban living settings, and lactose intolerance are also common among African Americans. These conditions promote opportunities for vitamin D deficiency to manifest and attenuate opportunities for participation in health-promoting behaviors by those affected. The common traits between vitamin D deficiency and type 2 diabetes merit careful attention.

In the past decade, a compelling body of evidence has emerged identifying the role of vitamin D in metabolic function extending beyond calcium regulation, bone mineralization, and cancer prevention to include glucose metabolism and a relationship with obesity. Vitamin D deficiency in African Americans is widespread, and deficiencies in vitamin D are indeed associated with obesity, impaired glucose metabolism, insulin resistance, and defective insulin secretion. African-American ethnicity is a risk factor for type 2 diabetes development, and evidence suggests vitamin D may also be a risk factor for its development.

African Americans are 77% more likely to incur a diagnosis of diabetes than non-Hispanic white Americans. New estimates from the Centers from Disease Control and Prevention indicate that 18% of African Americans have diabetes compared to 10.2% of non-Hispanic whites.

The reasons behind the higher prevalence rates of type 2 diabetes in African Americans are multidimensional. African Americans experience poverty, lactose intolerance, and obesity more often than other ethnic groups, and each of those may influence access to sources of vitamin D. Therefore, improving the understanding of comorbid conditions associated with vitamin D deficiency is an important health care priority.

To gain a better understanding of the health consequences that deficiency in vitamin D may trigger, common risk factors of vitamin D deficiency and type 2 diabetes in African Americans merit thorough consideration. 

 

This article is to increase awareness of the health consequences associated with vitamin D deficiency.

This article will highlight the shared attributes of vitamin D deficiency, type 2 diabetes, and obesity in this group. It will also define vitamin D deficiency and discuss normal recommendations for intake. Relationships between vitamin D deficiency, insulin resistance, and impaired insulin secretion will be discussed, as well as the role of diabetes educators in strengthening advocacy programs to prevent vitamin D deficiency.

Vitamin D: Background

Vitamin D is a fat-soluble nutrient that is obtained from dietary sources (some fortified) as D2 (ergosterol) or D3 (cholecalciferol).9 Cholecalciferol (D3) may also be produced in the skin when exposed to sufficient ultraviolet rays.10 Once obtained, vitamin D is hydroxylated in the liver to form 25(OH) vitamin D and used by the kidney to construct its biologically active form, 1-25(OH)2 vitamin D (calcitriol). The 25(OH) vitamin D3 has a half-life of several weeks, and hence, measurement of this level is appreciated as the gold standard for determining sufficiency in circulating vitamin D.

Cholecalciferol (D3) is largely found in fish, eggs, and meats, as well as in milk and foods that have been fortified. Ergosterol (D2) is a plant-derived source of vitamin D. Presently, only ergosterol (D2) is regulated by the Food and Drug Administration and available by prescription. Most over-the-counter vitamin D supplement preparations are vitamin D3 (cholecalciferol).

The risk for deficiency in vitamin D is substantial among African Americans and other ethnic groups with dark complexions. The elderly, people with sedentary lifestyles, and those who regularly wear clothes that cover most of the body also have an elevated risk for vitamin D deficiency. 

Sunlight stimulates vitamin D (cholecalciferol) production in the skin; hence, limited sun exposure from seasonal changes, sunscreen, pollution, or other causes reduces its production. 

Melanin acts as a natural sunscreen and limits vitamin D production; thus, vitamin D deficiencies in people with darker skin is common. Intake of vitamin D is also affected by the common occurrence of lactose intolerance in African Americans. Jarvis and Miller indicated that African Americans have lower intake of dairy food nutrients and that eating at least three foods in the dairy group daily may go far to minimise chronic disease risks. 

Milk is a vitamin D–fortified source of nutrition, and lactose intolerance can contribute to lower intake of vitamin D in people affected by it. Lactose intolerance is an exacerbating factor for vitamin D deficiency, but in sum, an aggregate of risks factors is most responsible for hypovitaminosis D collectively in African Americans.

How to prevent vitamin D deficiency?

The best ways to prevent a vitamin D deficiency are to eat foods that are rich in this nutrient and to spend some time outside each day. Some tips for avoiding a deficiency include: Maintaining a healthy body weight: Cycling or walking can provide both exercise and exposure to sunlight.

Getting enough, but not too much, vitamin D is needed to keep your body functioning well. Vitamin D helps with strong bones and may help prevent some cancers. Symptoms of vitamin D deficiency can include muscle weakness, pain, fatigue and depression.

Remember, self-care is a DIVINE responsibility. When you take care of YOU, you will thank your body later.

 

To your success!