A majority of the doctors South First spoke to agreed that there has been an ongoing debate for several years on the subject.
Foods rich in vitamin D on a wooden table. (iStock)
In a nation abundant with sunshine, the escalating cases of Vitamin D deficiency have sparked discussions among medical experts.
Gastroenterologist Dr Rajeev Jayadevan from Kochi recently highlighted, through a post on X, the urgent necessity for Vitamin D reference ranges that are tailored for the Indian population.
He raised concerns over India’s adoption of Western standards for what constitutes the “normal range”, suggesting they might be excessively high.
Jayadevan firmly advocated for a customised reference range for India, stating that “the reference range must be tailored to India [sic]”.
Vitamin D deficiency is being over-diagnosed: the “normal range” is set too high
Latest India data among healthy people show that if these levels are used, then 98% will be “insufficient or deficient”
TLDR: The reference range has to be customised for India. See slide.
1/3 pic.twitter.com/DNKsZxR1es
— Rajeev Jayadevan (@RajeevJayadevan) March 7, 2024
To delve deeper into this issue, South First engaged with medical professionals from various specialities to gather their perspectives on the diagnosis and prescription of Vitamin D supplements.
Dr Vijay Rao, the secretary-general of the Indian Medical Association’s Telangana chapter, explained to South First that Vitamin D deficiency means one does not have enough Vitamin D in their body.
Such a deficiency primarily causes issues with one’s bones and muscles, he added.
Rao noted that Vitamin D is crucial for the normal development and maintenance of bones, besides playing a significant role in the nervous, musculoskeletal, and immune systems.
There are several ways to obtain Vitamin D, the most common being sun exposure on one’s skin, though this may not be sufficient for individuals with darker skin, older adults, or those living in regions with limited sunlight, he explained.
Other sources of Vitamin D include dietary sources and nutritional supplements, added Rao.
“Despite all these methods to get Vitamin D, deficiency is a common worldwide problem,” he said.
The commonly used thresholds to interpret Vitamin D levels in the blood are measured in nanograms per millilitre (ng/ml).
These thresholds are based on Western standards and are often adopted by local laboratories in India for evaluating Vitamin D status.
The thresholds are:
These thresholds are meant to guide healthcare providers in diagnosing and managing Vitamin D status in individuals.
Dr Jayadevan raised questions on whether these Western-derived values are appropriate for all populations, given the variability in sun exposure, skin pigmentation, dietary habits, and genetic factors that influence Vitamin D synthesis and metabolism.
In his conversation with South First, Jayadevan delved into the nuances of establishing reference ranges, “When we say a lab value is normal or abnormal, there is an upper and lower reference range. Have you ever wondered how this reference range is created? It is based on the average value in a healthy population and two standard deviations to define the upper and lower limits.”
He further explained how geographical and ethnic differences influence these ranges, “For example, the average height range in Germany will not be the same as in Malaysia.”
Jayadevan also stressed the complexity of correlating Vitamin D levels with health outcomes, pointing out the variability in Vitamin D synthesis due to factors like diet, sun exposure, latitude, and seasonality.
He emphasised the need for a regional perspective when determining Vitamin D sufficiency, “Unlike in diabetes, a single universal upper limit of normal for Vitamin D level might not apply to the entire population of the world.”
He commended the Indian Academy of Paediatrics for establishing customised reference ranges for Indian children, which significantly differ from Western adult values.
He advocated for a similar approach for adults, especially in light of recent studies indicating that healthy young adults in India often have Vitamin D levels well below Western reference ranges.
He said, “Rather than labelling the entire population deficient, this suggests that the normal healthy values for India could be different. This is a knowledge gap that requires further study, so that doctors can be more focused when it comes to giving Vitamin D supplements to only those who truly benefit from it.”
Several doctors South First spoke to agreed that Vitamin D deficiency was definitely a major concern.
Source from the study published in Medical Journal Armed Forces in India, December 2023. (Supplied)
However, they cited several studies that have shown there might be overdiagnosing of this deficiency and there was a definite need for a comprehensive regional study and a standard for India.
Dr Sudhir Kumar, a noted neurologist from Apollo Hospitals, told South First, “It is true that Vitamin D deficiency is being overdiagnosed in India.”
He concurred with Jayadevan that the cut-off value of >30 ng/ml for normal Vitamin D level was too high.
Jayadevan cited a recent comprehensive study from JIPMER in Puducherry, which analysed Vitamin D levels across various regions of India, taking into account factors such as latitude and seasonality, and revealed that there was variation by latitude and season.
This revelation called into question the applicability of the so-called “normal range” of Vitamin D levels, suggesting a dire need for a tailored approach to Vitamin D deficiency.
Vitamin D levels are typically assessed through serum 25(OH)D concentrations, but correlation with health and disease is not firmly established, and varies by ethnicity, latitude, weather and assay, said the NIH paper on Vitamin D, as cited by Dr Jayadevan.
This approach acknowledged the diversity in Vitamin D metabolism and the myriad factors that can influence Vitamin D status, advocating for a more nuanced interpretation of Vitamin D levels that reflects the unique characteristics of each population.
Dr Sudhir Kumar said that overdiagnosing was leading to overprescription of Vitamin D supplements.
“A majority of healthy individuals have Vitamin D levels lesser than 30 ng/ml, as per studies done in various parts of India,” he noted.
“There is a need to use lower cut-offs to diagnose Vitamin D deficiency,” he went on to add.
“Below 12 ng/ml can be classified as Vitamin D deficiency and between 12 and 20 ng/ml can be classified as Vitamin D insufficiency,” said Dr Kumar.
He added that those with Vitamin D levels above 20 ng/ml could be considered normal in India.
Dr Kumar explained that Vitamin D level cut-offs could not be the same for everyone. He said multiple factors affected these levels.
For example:
There is seasonal variation too. Studies conducted in summer showed higher Vitamin D levels (29.9 ng/ml) as compared to those conducted in winter (15.1 ng/ml).
A majority of the doctors South First spoke to agreed that there has been an ongoing debate for several years on research on the subject.
They added that the Health Ministry and the Indian Council of Medical Research (ICMR) must put an end to this discussion with proper region-based research.
“This debate has been going on for a long time, and the research is long due. They should be put into action with systematic reviews! We at the Indian Association of Paediatrics have our own with lower cut-off levels as above 20 is considered as normal instead of 30,” Dr Ramchander Neeli, a member of IMA Telangana and a senior paediatrician, told South First.
Meanwhile, Dr Srisailam, the secretary general of the IMA’s Nizamabad chapter, explained that Vitamin D deficiency is found even in farmers, who majorly work in the fields and are exposed to sunlight.
“Even they are at insufficient levels, and they are totally asymptomatic. So, there is a definite need for extensive studies and a change in the diagnostic method. It might vary from dark skin to light ones, race to race, and geographical location,” he said.
However, Dr Tanabuddi Anil Kumar, a civil surgeon at the Area Hospital in the Nalgonda district of Telangana, said he was fine with the existing cut-off, and that it was good to give supplements to those who had Vitamin D levels below 30 ng/ml.
The good doctor himself gives intramuscular 6-lakh international unit (IU) Vitamin D injections once in 10 days, two or three times for symptomatic patients whose Vitamin D levels are below 10 ng/ml. Symptoms include but are not limited to polymyalgia, plantar fascitis, lethargy, and stress fractures.
For those with Vitamin D levels of 10-20 ng/ml, he suggested one dose of 6-lakh IU Vitamin D injection, followed by daily Vitamin D supplements.
For those above 20 ng/ml, he suggested starting a weekly dose of 60,000 IU Vitamin D supplements for eight to 12 weeks, followed by daily supplements for one to two months.
He said, “With this protocol, I have seen very good responses from the patients.”
Dr Vijay Rao said the best way to prevent Vitamin D deficiency was to ensure enough of it in one’s diet, as well as sun exposure.
But one must remember that excessive sun exposure could damage the skin, he noted.
Food that could help were fatty fish, beef liver, mushrooms, egg yolk, and cod liver oil.
Though one can get Vitamin D from fortified foods, it’s better to check the nutrition labels to find out if the food has Vitamin D.
Foods that often have added Vitamin D include:
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