Keeping up with the alphabet soup of vitamins

Vitamin D has been a polarizing topic for the past several years in health care. Deficiency of vitamin D is considered the most common nutritional deficiency worldwide. Until recently, most of our focus was on vitamin D deficiency in infants and women during pregnancy. Vitamin D deficiency can cause abnormalities in calcium and bone metabolism. In children, this deficiency can result in a group of skeletal disorders more commonly known as rickets. This article will attempt to broaden your understanding of vitamin D deficiency, who is at risk, what adverse effects result from low levels of vitamin D, and how to prevent/treat this issue.

What is vitamin D?

Known as an important hormone precursor, vitamin D can be found in two different forms: Ergocalciferol, more commonly known as D2, and Cholecalciferol, or D3. It works to help calcium absorption in the small intestine. With a vitamin D deficiency, only 10-15 percent of dietary calcium is absorbed, compared to around 40 percent in those with adequate levels. Along with the parathyroid hormone (PTH), vitamin D maintains skeletal mineralization and attempts to keep adequate levels of calcium in the blood. These are all important functions in the body.

What is a normal vitamin D level?

In 2011, the Journal of Clinical Endocrinology Metabolism published an article that serves a clinical practice guideline. In this publication they recommended using a lab test that tested 2.5-hydroxyvitamin D [2.5(OH) D], and defined vitamin D insufficiency as a 2.5(OH)D of 21-29 ng/ml. The guideline went on to define vitamin D deficiency as a 2.5(OH)D below 20 ng/ml.

Where in the world can we get a source of vitamin D?

Vitamin D is a fat-soluble vitamin. Vitamin D2 comes from plant sources and some fish such as cod, tuna, salmon and swordfish. Other decent dietary sources include milk, yogurt and fortified orange juice. Vitamin D3 is believed to be better than vitamin D2, and the most common source is the sun. Decades ago, children and adults spent much more time outside, so the prevalence of vitamin D deficiency was much lower. With evolving technologies and an overall shift to more inside activities, the percentage of Americans with vitamin D deficiency will continue to rise.

Those who are exposed to the sun in a bathing suit and receive a slight “pinkness” in the skin are estimated to have received between 10,000 to 25,000 International Units (IU) of vitamin D. Furthermore, vitamin D produced by the skin is thought to last twice as long in the blood stream versus that ingested. Of course, prolonged sun exposure can lead to unwanted skin issues such as cancer; so the use of sunscreen is beneficial but can lead to decreased amounts of vitamin D absorption by more than 95 percent. Other factors that can impair vitamin D absorption are increased skin pigmentation (may take up to five times longer to make the same amount of vitamin D as a person with lighter skin tone) and increased age. Also, during the winter, the creation of vitamin D by the skin is lower.

How much vitamin D do I need on a daily basis?

The amount varies based on age and whether or not deficiency exists. Infants should get 400-1,000 IU daily. Males and females under the age of 19 should obtain 600-1,000 IU daily. All other adults should receive at least 1,500- 2,000 IU daily. The only group requiring higher levels is breastfeeding women, who are recommended to get 4,000-6,000 IU a day. As you can see, there is a wide range of recommended doses based on the individual.

What are the effects of chronic low vitamin D levels?

Studies have linked low vitamin D levels to increased cardiovascular mortality. In addition, vitamin D has been linked to increased risk of Type 2 diabetes, worsening fatigue and depression, and inflammation throughout the body. Several studies show that in those over 65 years of age vitamin D supplementation reduces the risk of falling. Researchers are looking at the correlation between vitamin D level and Alzheimer’s disease.

Who should be tested for vitamin D deficiency?

This is where many questions are raised by different institutions. Below are the recommendations of who should be screened for low vitamin D levels outlined in the latest clinical practice guideline.

Please note, always talk to your primary care provider about your risk for vitamin D deficiency and what his or her position is on the subject.

People who should be screened for low vitamin D levels.

People with rickets, osteomalacia, osteoporosis, chronic kidney disease, hepatic failure, malabsorption syndromes, Hyperparathyroidism, people taking anti-seizure medications, glucocorticoids, AIDS medications, antifungals and cholestyramine, African-American and Hispanic children and adults, pregnant and lactating women, older adults with history of falls and non-traumatic fractures, obese children and adults, people with granuloma-forming disorders and people with some lymphomas.

Graham Rachal, DNP, FNP-C is board-certified through the American Academy of Nurse Practitioners and completed his Doctorate of Nursing Practice through the University of South Alabama with a concentration and research emphasis in diabetes management. He is a member of Sigma Theta Tau, American Association of Nurse Practitioners and the Louisiana Association of Nurse Practitioners. He can be reached at (318) 798-4488, at his third-floor offices, 1455 East Bert Kouns Industrial Loop, Suite 300, Internal Medicine. For more information, visit the website http://www. highlandclinic.com/staff/graham-w-rachal-fnp.