Severe vitamin D deficiency linked to risk of premature death says new research

Vitamin D, also known as Calciferol is a group of fat soluble secosteroids. It helps regulate the level of calcium, phosphate, and magnesium in the body. This helps in maintaining good bone health, aiding in its healing, growth, as well as maintaining the bone structure. Vitamin D also helps in keeping other systems healthy like nervous system, immune system, as well as musculoskeletal system.  There is now evidence based research linking vitamin D and premature mortality.

Low 25-hydroxyvitamin D [25(OH)D] concentrations are associated with an increased risk of mortality. This has been shown in different cohort studies including general populations, as well as various patient cohorts.

New research from the University of South Australia gives strong evidence that vitamin D deficiency is associated with premature death, prompting calls for people to follow healthy vitamin D level guidelines. Published in Annals of Internal Medicine, the study found that the more severe the vitamin D deficiency, the greater the risk of mortality.  Specifically, the researchers estimate that the odds of all-cause mortality increase by 25% for individuals with vitamin D serum levels of 25 nmol/L compared to people with serum concentrations of 50 nmol/L.

What is vitamin D deficiency?

Sometimes a person is unable to obtain the vitamin d they require naturally. A doctor can determine the levels of vitamin D in body through blood tests.

• Experts generally define vitamin D deficiency as serum 25(OH)D levels below 30 nmol/L.
• Vitamin D concentrations between 30–49 nmol/L are considered insufficient

Other evidence suggests that vitamin D deficiency is defined as serum 25(OH)D concentrations of less than 50 nmol/L, and severe vitamin D deficiency occurs when serum concentrations fall below 30 nmol/L.

Symptoms of vitamin D deficiency

In addition to the results of the blood test readings, symptoms of vitamin D deficiency include:

• bone fragility, osteoporosis, or both
• bone pain
• tiredness
• muscle weakness, pain, or twitching
• stiff joints

Relation between vitamin D and mortality

According to Dr. Elina Hypponen, director of the Australian Centre for Precision Health at the University of South Australia and senior author of the new study, the research team wanted to evaluate whether higher vitamin D status can lower the risk of premature mortality and whether this effect is similar for people who have low vitamin D levels and for these who already have sufficient concentrations.

The research team recruited 307,601 participants from the U.K. Biobank to examine associations between vitamin D and mortality risk. The participants were between the ages of 37–73 years at the time of recruitment, and all were of white European ancestry.

Scientists used a technique called “Mendelian randomization” for the study, which allows the researchers to use genetic variation to look for causal relationships between modifiable risk factors — in this case, vitamin D deficiency — and health outcomes, such as mortality risk.

They obtained the participant’s genetic data and measurements of serum 25-hydroxyvitamin D 25(OH)D.

Upon analysis, researchers found over a 14-year time span that a person’s death risk decreased significantly when their vitamin D levels increased.

Scientists also reported an association between lower vitamin D levels and deaths caused by:

• Cancer
• Cardiovascular diseases
• Respiratory diseases

Why would vitamin D levels impact mortality risk?

Previous genetic research by Hypponen and her colleague Ang Zhou, PhD, found an association between low vitamin D status and higher C-reactive protein — an inflammatory biomarker in the blood.

“It is possible that lower inflammation may in part help explain these findings; however, there are also many other mechanisms,” Hypponen said.

“It is important to remember that vitamin D is a pro-hormone, which has receptors throughout the body, including most major organs. If we allow the levels of this hormone to go very low, it is possible that multiple systems get disrupted, leading to an increase in overall frailty, and as our results suggest, an increase in premature mortality.”

How to get more vitamin-D?

According to the National Institutes of Health (NIH), the average recommended amount of vitamin D for healthy adults is 600 International Units (IU) per day. Adults 71 years and older should try to get 800 IU per day.

Moreover, the 2011 Endocrine Society Clinical Practice Guidelines suggest that treatment for vitamin D deficient adults is 50,000 IU of vitamin D2 or vitamin D3 once a week for eight weeks or 6000 IU of vitamin D2 or vitamin D3 daily.

Then, once 25(OH)D levels are adequate, the recommended maintenance dose is 1500–2000 IU per day

Eating more foods containing vitamin D and getting more sunlight can help increase vitamin D levels in case of deficiency.

Recommended food sources of vitamin D include:

• salmon
• egg yolks
• dairy products fortified with vitamin D

G in daily walks outside in the sun will is helpful in treating vitamin D deficiencies as well. However, it is important to use sunscreen.

If someone is found to be vitamin D deficient, their healthcare professional might ask them to take in additional supplements.