Vitamin D (25-DiHydroxyvitamin D) Blood Test
Why You Need to Test Your Vitamin D Level
According to the International Journal of Health Sciences, “Vitamin D deficiency is a global vitamin deficiency. With all the medical advances of the century, vitamin D deficiency is still epidemic. Over a billion people worldwide are vitamin D deficient or insufficient. Yet no international health organization or governmental body has declared a health emergency to warn the public about the urgent need of achieving sufficient vitamin D blood levels.”
Diseases Associated wth Low Vitamin D3
- Acute Respiratory Tract Infections
- Osteoporosis
- Obesity
- Diabetes
- Hypertension
- Depression
- Fbromyalgia
- Chronic Fatigue Syndrome
- Multiple Sclerosis (MS)
- Dementia and Alzheimer's Disease
- Cancers of the Breasts, Prostate and Colon
Vitamin D has hormone like activity. It regulates the functions of over 200 genes and is essential for growth, development and optimal immune function. Vitamin D deficiency is associated with susceptibility to acute respiratory tract infections, osteoporosis, obesity, diabetes, hypertension, depression, fibromyalgia, chronic fatigue syndrome and neuro-degenerative diseases including Multiple Sclerosis and Alzheimer’s disease. Vitamin D deficiency has even been associated with the development of cancers, especially breast, prostate, and colon cancers.
Deficiency Risk
Vitamin D poses a unique deficiency risk, because as we age our bodies become less and less efficient at producing Vitamin D. Individuals over the age of 70, produce 70 percent less Vitamin D than an individual in their 20s.
Estimates place the percentage of seniors who are Vitamin D deficient at 95 percent. Individuals in climates which receive less daylight, or individuals who do not go outside often, are at an even higher risk of Vitamin D deficiency.
Vitamin D Deficiency of Pandemic Proportions!
According to Healthline, it is estimated that about 1 billion people worldwide have low levels of Vitamin D in their blood. About 42% of the US population is Vitamin D deficient. However, this rate rises to 82% in black people and 70% in Hispanics, because the increased amount of melanin in darker skin blocks the absorption of UV-B sunlight, which is required to make Vitamin D in the skin.
According to research updated on September 21, 2020, in Medscape Endocrinology online, Vitamin D insufficiency is highest among people who are elderly, institutionalized, or hospitalized. In the United States, 60% of nursing home residents and 57% of hospitalized patients were found to be Vitamin D deficient.
The major circulating form of vitamin D is 25-hydroxy Vitamin D [25(OH)D]; thus, the total serum 25(OH)D level is currently considered the best indicator of vitamin D supply to the body from cutaneous synthesis and nutritional intake.
The reference range of the total 25(OH)D level is 25-80 ng/mL. Vitamin D deficiency is defined by most experts as a serum Hydroxy Vitamin D [25(OH)D] level of less than 20 ng/mL (50 nmol/L). The average adult Vitamin D blood level across the US is 20-26 ng/mL.
LABORATORY Blood Levels of Vitamin D (25-Hydroxy Vitamin D)
- Deficiency: Less than 20 ng/ml (50 nmol/L)
- Insufficiency: 21-29 ng/mL (52-72 nmol/L)
- Sufficiency: 30 ng/mL (75 nmol/L) or above
- Optimal: 50-70ng/mL(125-175nmol/L)
- Excessive: greater than 100ng/mL (250nmol/L)
Low Vitamin D levels are found most frequently in northern latitudes and are associated with low levels of sunlight, older age, darker skin and a diet deficient in Vitamin D rich foods.
Researchers found that people in the Nordic countries have higher levels of Vitamin D because they tend to seek more outdoor sunshine, consume more Vitamin D supplements and eat more fish high in Vitamin D, which may account for their higher blood levels. The mean level of Vitamin D in Nordic countries is 18.0 ng/mL.
Vitamin D insufficiency is obviously not restricted only to the elderly and hospitalized population. Several studies have found a high prevalence of Vitamin D deficiency among healthy, young adults as well. Nearly two thirds of healthy, young adults in Boston become vitamin D insufficient at the end of each winter.
An analysis of data of almost 3000 US children and adolescents (age, 6-18 y) from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 indicated that, based on current Institute of Medicine Committee guidelines, about 10.3% of this population (an estimated 5.5 million) had inadequate vitamin D (25(OH)D) blood levels (< 16 ng/mL), and 4.6% (an estimated 2.5 million) had levels placing them at risk of frank deficiency (< 12 ng/mL). Adolescents (age, 14-18 y) and obese children had the highest risk of 25(OH)D deficiency and inadequacy, and these risks were also higher among girls than boys (of any age and body mass index) and among nonwhite children.
How Does Vitamin D Work?
Vitamin D works by enhancing calcium metabolism, cardiovascular function and immunity. The active form of Vitamin D is essential to the body’s innate and adaptive immune systems, where it produces specialized Anti-Microbial Peptides (AMPs) known as Cathelicidin and Defensins, which reduce the survival and replication of viruses.
Vitamin D also assists in regulating inflammatory cytokines. Vitamin D initially enhances inflammatory cytokines to kill viruses and other microbes and then suppresses inflammation to prevent a cytokine storm when the infection is under control. Vitamin D is widely recognized for its ability to balance the immune response.
General Health Benefits of Vitamin D
Immune Health - Vitamin D is believed to play a factor in regulating the immune system. Supplementation with Vitamin D is believed to be associated with a lower risk of infections and a better ability to fight off infections.
Multiple Studies show that Low blood levels of Vitamin D are associated with an increased risk of getting COVID-19, suffering a more severe illness due to the infection and an increased risk of dying from it.
Osteoporosis - More than 40 million Americans are at risk of Osteoporosis, a disease marked by low bone strength and an increased risk of fractures. Studies have shown that individuals who take a supplement with calcium and Vitamin D have stronger bones and are less likely to suffer from fractures.
Cancer - Evidence suggests that Vitamin D supplementation affects the risk of Colon, Breast, and Prostate Cancer. Several studies have shown that individuals taking a Vitamin D supplement had lower chances of developing these types of cancer.
Brain/Nervous System - Vitamin D to a wide range of brain functions including learning and memory.
Vitamin D & The Brain
Vitamin D activates nerves in the brain and spine which are involved with neurotransmitter creation and nerve growth. Researchers also believe that Vitamin D protects brain neurons and reduces inflammation; inflammation is a common characteristic of Alzheimer's.
Vitamin D is one of the most important supplements, especially for individuals over the age of 65. Vitamin D deficiency is linked to serious health issues and the majority of individuals over the age of 65 are believed to be Vitamin D deficient due to a unique reason discussed below.
Vitamin D and Alzheimer's Disease
- Studies have shown that individuals whom are Vitamin D deficient are at an increased risk for developing Alzheimer's disease or dementia.
- Scientists believe that the majority of seniors are deficient in Vitamin D because the body produces less as we age.
There is a significant amount of evidence linking Vitamin D deficiency to cognitive decline, Alzheimer's, and dementia.
Two studies conducted by Neuroscientists at the Universities of Cambridge and Manchester, England examined 4,500 individuals over the age of 65 and both found that lower levels of Vitamin D were associated with worse mental performance. The study conducted at the University of Cambridge found that individuals who were severely deficient for Vitamin D had double the risk of being cognitively impaired when compared to individuals with ideal Vitamin D levels. [1.Serum 25-Hydroxyvitamin D Concentration and Cognitive Impairment] [2.Association between 25-hydroxyvitamin D levels and cognitive performance in middle-aged and older European men]