Vitamin D Deficiency (cont.)
Betty Kovacs, MS, RD
Betty is a Registered Dietitian who earned her B.S. degree in Food and Nutrition from Marymount College of Fordham University and her M.S. degree in Clinical Nutrition from New York University. She is the Co-Director and Director of nutrition for the New York Obesity Research Center Weight Loss Program.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In this Article
- What is vitamin D?
- What does vitamin D do for one's health? What are symptoms and signs of vitamin D deficiency?
- What causes a vitamin D deficiency?
- How is a vitamin D deficiency diagnosed?
- What is the treatment for a vitamin D deficiency?
- Can vitamin D deficiency be prevented?
- What are symptoms and signs of an excessive vitamin D intake?
- Vitamin D FAQs
- Find a local Doctor in your town
How is a vitamin D deficiency diagnosed?
All it takes is a simple blood test to find out if you are deficient in vitamin D, but determining the optimal level is not quite as simple. There is a lot of controversy about what the optimal levels and deficient levels are. The test will measure your 25(OH)D level. The Institute of Medicine set the guidelines for serum (blood) 25(OH)D levels to be as follows:
- Deficiency: 25(OH)D level BELOW 12 ng/mL
- Inadequate: 25(OH)D level BETWEEN 12-20 ng/mL
- An adequate 25(OH)D level is between 20-50 ng/mL
- Excessive: 25(OH)D level over 50 ng/mL
Many believe that 30 ng/mL should be the minimum for an adequate level. According to the NHANES national survey the average vitamin D level has dropped from 30 ng/mL in 1988-1994 to 24 ng/mL in 2001-2004. The percentage of those below 10 ng/mL has increased from 2% to 6%, and the percentage with levels of 30 or above has decreased from 45% to 23%. With the levels changing at this rate, this really has become an epidemic.
What is the treatment for a vitamin D deficiency?
The amount of vitamin D that is needed to correct a deficiency will depend on the severity of the deficiency. When the blood level is below 30 ng/mL, a minimum of 1,000 IU/day of vitamin D3 will be needed for children and 1,500 to 2,000 IU/day of vitamin D3 for adults. Another rule of thumb is for every 1 ng/mL increase in your blood level you need an additional 100 IU/vitamin D per day.
A task force for the Endocrine Society reviewed the research and made the following recommendations:
- For children 1-18 years of age who are vitamin D deficient, we suggest treatment with 2,000 IU/d of vitamin D2 or vitamin D3 for at least six weeks or with 50,000 IU of vitamin D2 once a week for at least six weeks to achieve a blood level of 25(OH)D above 30 ng/ml, followed by maintenance therapy of 600-1,000 IU/day.
- We suggest that all adults who are vitamin D deficient be treated with 50,000 IU of vitamin D2 or vitamin D3 once a week for eight weeks or its equivalent of 6,000 IU of vitamin D2 or vitamin D3 daily to achieve a blood level of 25(OH)D above 30 ng/ml, followed by maintenance therapy of 1,500-2,000 IU/day.
- In obese patients, patients with malabsorption syndromes, and patients on medications affecting vitamin D metabolism, we suggest a higher dose (two to three times higher; at least 6,000-10,000 IU/day) of vitamin D to treat vitamin D deficiency to maintain a 25(OH)D level above 30 ng/ml, followed by maintenance therapy of 3,000-6,000IU/day.
For optimal absorption, you want to take your supplement with the meal that contains the most fat. Vitamin D is a fat-soluble vitamin and requires fat for absorption. A recent study instructed people to take their supplement with their largest meal (typically the one with the most fat), and in three months, their blood levels went up an average of 56.7%.
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