Assessing Vitamin D Sufficiency in all our patients
For many years, clinicians have been aware that Vitamin D sufficiency plays a critical role in bone remodeling. However, numerous recent studies have shown that Vitamin D also plays a key role in maintaining other aspects of overall health. Research confirms that adequate Vitamin D is critical for normal cellular functions in many other organ systems. In fact, many do not consider Vitamin D as a true vitamin but may act more like a hormone that is able to signal over 2000 genes in the body and over 36 organ systems.
The Emerging Link between Vitamin D Sufficiency and General Health or Disease Incidence
A Closer Look at the Mounting Research
Studies have also revealed that higher levels of Vitamin D are associated with reduced risk of certain malignancies, including:
- Prostate cancer
- Endometrial cancer
- Skin cancer
- Pancreatic cancer
- Colorectal cancer
- Breast cancer
Vitamin D deficiency has been linked to increased risk of developing:
- Autoimmune diseases
- Multiple sclerosis
- Type 1 diabetes
Deficiency has also been associated with:
- A worsened prognostic state in patients diagnosed with certain cancers or cardiovascular disease
- Seasonal Affective Disorder ( a type of depression)
- Cardiovascular Disease
Vitamin D deficiency in pregnancy is associated with:
- Increased odds of primary cesarean delivery
The Known Link between Vitamin D Sufficiency and Healthy Bone Structure
Vitamin D Classic Physiology
Providers have known that Vitamin D sufficiency is important in calcium homeostasis and in the maintenance of healthy bone. Vitamin D stimulates the absorption of calcium and may also serve to increase calcium and phosphate resorption. Deficiency of Vitamin D leads to the mobilization of calcium from bone, which can lead to osteoporosis, osteomalacia, and rickets.
It is estimated that up to 50% of apparently healthy children and young adults are Vitamin D deficient. The prevalence of Vitamin D deficiency in the US has been reported at 25% to 57% in adults.
What risk factors contribute to Vitamin D deficiency?
- Age: older adults are at increased risk
- Inadequate sun exposure
- Insufficient dietary intake of Vitamin D
- Living at higher latitudes
- A dark complexion (increased skin pigmentation/high melanin levels)
- Malabsorption syndromes, liver disease and kidney disease
Interestingly, even patients who even live in areas of the sunbelt have been found to be deficient. One important reason is due to the rise in the incidence of skin cancer and most are likely to use UV blocking creams which will inhibit the activation of Vitamin D in the skin. Therefore, assessing total Vitamin D levels (D2 + D3) becomes very important in all patients.
Maintaining Vitamin D Sufficiency
There are two sources of Vitamin D: diet and exposure to sunlight. Energy from the sun converts a precursor in the skin to Vitamin D3. Vitamin D levels can be increased by spending some time in the sun. The normal diet is very low in Vitamin D. Most foods, with the exception of fatty fish oils, contain little Vitamin D. Some recent studies have shown that Vitamin D supplementation with D3 maybe more effective than supplementation with D2. Vitamin D is available without prescription.
It is best to take your Vitamin D supplement (if taken orally) with your largest fat meal and recheck a blood test in 3-4 weeks. Once achieving stable values it is reasonable to check once per year.
DiaSorin Classification of 25-OH Vitamin D Status
Deficiency- less than 10 ng/mL
Insufficiency- 10-30 ng/mL
Sufficiency- 30-100 ng/mL
Although 30 or greater is considered normal by many clinicians, in a more recent review of a number of studies, it appears that most patients will benefit clinically when higher values (between 50-60 ng/ml) are achieved. However, levels greater than 100 ng/ml may predispose to Atrial Fibrillation.