Around 50% of the global population has vitamin D deficient, increasing the risk of health problems including bone fractures, diabetes, heart disease and even certain types of cancer, the review says. Tailoring vitamin D supplementation to factors such as the season and a person’s genetics, blood test results and lifestyle could help to prevent and treat these conditions.
“Vitamin D is an essential nutrient playing an important role in promoting overall health and well-being,” wrote review co-author Tamara Sorić of the Psychiatric Hospital Ugljan in Ugljan, Croatia and colleagues.
They noted that the appropriate dosing and exact benefits of vitamin D supplements in health conditions are still inconclusive, adding that “further studies are needed to provide more comprehensive insight into the topic and help us make more concrete conclusions.”
The vitamin D deficiency 'global pandemic'
Vitamin D plays a key role in maintaining healthy levels of calcium and phosphate in the blood, and the majority of our intake typically comes from vitamin D produced in the skin during exposure to ultraviolet (UV) rays in sunlight. The rest comes from our diet, with the richest sources including fatty fish, egg yolk and mushrooms.
Factors driving the vitamin D deficiency in the global population include people spending more time indoors, the rising proportion of elderly people—whose skin is less effective at synthesizing vitamin D—and other factors such as skin color and geographic location. Dietary supplements can thus help populations to stay healthy.
“Taking vitamin D is generally considered safe if it is taken in recommended doses,” the researchers wrote. “However, too much of a good thing can sometimes do more harm than good. The uncontrolled intake of excessively high doses of vitamin D can have unwanted and very serious consequences.”
In the future, the review suggests that precision supplementation could address vitamin D deficiency in people in risk groups, with the specific approach varying “based on available resources, technology and scientific advancements.”
Martin Hewison, director of the Institute of Metabolism and Systems Research at the University of Birmingham, who was not involved in the review, sees vitamin D overdose as a rare event despite high media attention. “I think that it is more cost effective to assume that vitamin D insufficiency is common across the globe and therefore national fortification programmes are the priority,” he said.
For example, parts of North America are fortifying products such as milk and orange juice with vitamin D, and many countries should have a national plan to improve intake of the vitamin. “The technology to add vitamin D to specific food such as flour has improved a lot in recent years so there is no excuse not to do this,” Hewison said.
The future of vitamin D supplementation
Going forward, digital health tools and wearable devices could be used to predict someone’s vitamin D intake by measuring their natural light exposure, just like they monitor glucose and sports activities today, suggests the review. Supplements could also be used to enhance the effect of therapies for related conditions such as cancer.
“Vitamin D has been linked to many human health issues outside the skeleton but getting clinicians to include vitamin D supplements as part of a treatment for these diseases is difficult,” Hewison said. “However, in many cases where patients are analyzed as part of management of cancer or autoimmune disease, they may be found to be vitamin D deficient and so doctors will, as a matter of course, treat this deficiency.”
The role of vitamin D in many diseases is becoming increasingly clear in the growing body of research. Additionally, more effective and bioavailable types of vitamin D supplements could be developed with new delivery methods such as nanoparticles or liposomal formulations.
“The field of vitamin D research is very broad and there are so many exciting areas that will release results soon,” Hewlson added. “However, we still need to get the basics sorted—what are the optimal levels of vitamin D for a human and how can we best achieve this?”
Source: Nutrients
2024, 16(8), 1176, doi: 10.3390/nu16081176
“The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?”
Authors: Mladen Mavar et al.