Vitamin D Deficiency: Implications Across the Lifespan

Rebecca Wike Malone; Cathy Kessenich


Journal for Nurse Practitioners. 2008;4(6):448-456. 

In This Article

Clinical Implications

Dietary Intake

In clinical practice, nurse practitioners can recommend diets that are higher in vitamin D. These foods include milk fortified with vitamin D, fortified cereals, and oily fish. Oily fish are the best sources of vitamin D. A key point with these fish is that there is a difference in vitamin D content in farm-raised versus wild fish.[28] The only cooking style that affected vitamin D content was frying in vegetable oil, which significantly reduced the vitamin D content ( Table 1 , Table 2 ).

In comparison to fish, milk provides 97.60 IU of vitamin per 8-ounce serving; therefore, 2 servings of milk a day will provide approximately 200 IU of vitamin D.[19] While these foods are helpful in maintaining adequate levels of vitamin D, daily supplementation is still recommended to ensure consistency in serum vitamin D levels.


Current research has determined that the daily recommended intake for most people is 1000 IU.[1,2,11,12] Supplementation of vitamin D can be obtained through daily multivitamins in addition to diet. The average daily adult multivitamin contains 400 IU of vitamin D. Children's vitamins vary their formularies between 200 to 400 IU per tablet or teaspoon. Depending on the patient's diet and the formulary of their multivitamin, practitioners can recommend 1 to 3 vitamins daily, 1 vitamin every 8 to 12 hours. If the patient presents with a frank insufficiency (serum level less than 10 ng/mL) they can be treated with a prescription of vitamin D2 50,000 IU once per week for 6 to 8 weeks, with serum levels drawn afterward to ensure a level greater than 32 ng/mL.[2]

Medications That Prevent Vitamin D Absorption

There are multiple drugs prescribed on a regular basis in primary care that can inhibit the absorption of vitamin D. These medications include anticonvulsants, thiazide diuretics, corticosteroids, nicotine, cimetidine, cholesterol-lowering agents (ezetimibe), heparin, and diet agents (Xenical and Alli) ( Table 3 ).


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.