Vitamin D

There has been an incredible surge of interest in vitamin D in recent years, as evidenced by research articles that are being published monthly or more frequently. If you use information services that keep you abreast of newly published studies, such as that provided by MDLinx.Com (www.mdlinx.com), then you know how much we have been learning about vitamin D. Although “vitamins” per se cannot be directly synthesized by the body and are obtained only through the diet, in the case of vitamin D, people are capable of synthesizing adequate amounts without ever obtaining it from their diet. Therefore, vitamin D is more correctly classified as a hormone, in that it is produced by the body and serves as a chemical messenger to signal biological responses and actions. Vitamin D is chemically similar to other steroid hormones, such as testosterone, estradiol, and cortisol, and all share cholesterol as their parent precursor.

While both vitamins D2 (ergocalciferol) and D3 (cholecalciferol) are believed to be effective, D3 is generally considered the preferred choice due to its use in successful clinical trials. What is actually measured to determine levels is calcidiol, commonly referred to as 25(OH)D, the major circulating metabolite of vitamin D. Current literature is in general agreement that the concentration of 25(OH)D should be at least 30 ng/mL.

In past years, vitamin D was considered adequately dosed at 400 units per day; recent studies show that dose is far too low for most patients. Patients who are being properly monitored require much higher doses, and an upper daily limit of 10,000 units is proper for the appropriately monitored patient. In fact, the Food and Nutrition Board presents data that suggests administering vitamin D in the short term and large doses, such as 50,000 IU per week for 8 weeks, as a safer dosing regimen than smaller daily doses. Deficiencies in vitamin D are related to a decline in exposure to sun (more indoor lifestyles), use of sunscreens, and sun-avoidance tactics.

BONE FRACTURES

Several studies reveal that low levels of vitamin D were associated with increased incidence of fractures, particularly hip fractures.

According to the Linus Pauling Institute, a prospective cohort study of over 70,000 postmenopausal women found that women who consumed at least 600 IU/day of vitamin D, either from diet or supplements or both, had a 37% decreased risk of hip fracture compared to women who consumed lower than 140 IU/day of vitamin D.

MUSCLE PAIN AND WEAKNESS

In a study by the Linus Pauling Institute, it was found that muscle pain and weakness were primary symptoms of vitamin D deficiency.

A study of patients with muscle pain with no apparent cause found that 93% of the participants had vitamin D deficiency.

Several other studies have shown a decreased risk of falls for those patients with adequate levels of vitamin D, suggesting that vitamin D may improve muscle strength, thus making patients more stable.

CARDIOVASCULAR

Vitamin D has also shown several effects in the cardiovascular system, and vitamin D receptors are found in the heart tissue.

The NHANES III trial found an inverse relationship between vitamin D levels and hypertension, diabetes, hyperlipidemia, and obesity.

The Framingham Study found that the risk for heart attack, ischemia, stroke, or heart failure was increased by 53% to 80% in patients who were deficient in vitamin D.

Hypertension

Pertaining to hypertension, studies have shown some conflicting results:

One study in patient with type 2 diabetes found that a single dose of 100,000 IU of vitamin D3 reduced patient’s blood pressure an average of 14 mmHg while improving endothelial function.

CANCER

Cancer is another topic where vitamin D deficiency has been studied. Vitamin D deficiency has been linked to the following cancers:

• Breast
• Colon
• Endometrial
• Non-Hodgkin’s lymphoma
• Ovarian
• Prostate

Much more research is needed in the use of vitamin D and disease prevention. However, it is safe to say that making sure patients have normal vitamin D levels and supplementation, if needed, would be a good recommendation to the practice of patient care.

Article Referenced from:

Biundo, Bruce. “Providing Consultation Services for Wellness Issues Related to Exercise, Weight Management, and Nutritional Support: Key Lifestyle Modifications for Healthier Aging.” International Journal of Pharmaceutical Compounding. 14.1 (2010): 28-30.