Unexpected Reality for Vitamin D Takers

This article originally appeared on The Epoch Times and was republished with permission.

Guest post by Sheramy Tsai

One in five Americans regularly reach for vitamin D supplements, yet most are unaware that they’re taking not just a vitamin— but a hormone.

While renowned for bolstering bone strength and immune health, vitamin D’s story is not straightforward. A blend of myth and established science invites a closer look into its true nature and impact.

Vitamin D: Understanding Its Dual Role

Vitamin D stands apart in the world of nutrients. It’s a sun-sourced substance acting as both a nutrient and a hormone. This dual role is significant, as hormones, which orchestrate many bodily functions, aren’t typically taken as supplements like vitamins.

Endocrinologist Dr. Michael Holick, a leading vitamin D expert, tells The Epoch Times, “The body more effectively utilizes vitamin D when it’s naturally synthesized from sunlight, compared to standard supplement doses.” This difference is key to understanding vitamin D’s health role and the complexities of supplementing a hormone.

Unlike most nutrients, the hormonal nature of vitamin D means it has a broader systemic impact, influencing not just bone health but also immune function, cell growth, and inflammation control. This understanding is crucial in guiding medical approaches to its use, including the potential risks and benefits of supplementation.

Beyond Bone Health

Vitamin D is more than just a bone health and immune system booster. Its multifaceted role in the body impacts everything from mood regulation to cardiovascular health.

At its core, vitamin D is vital for calcium absorption in the gut, and essential for bone strength and health. “Without enough Vitamin D, the body can only absorb 10–15 percent of calcium,” Dr. Alex Foxman, a leading internist and preventive care specialist, told The Epoch Times. Insufficient calcium can result in weaker bones and heightened fracture risks.

Moreover, vitamin D is pivotal for immune health. Dr. Holick observes, “Vitamin D receptors are in almost every cell, including immune cells.” Proper levels are vital for a balanced immune response and preventing autoimmune disorders.

Dr. Nathan Goodyear, an integrative cancer physician and director of Brio Medical, an integrative cancer treatment center in Scottsdale, Arizona, stresses vitamin D’s essential role in immune functionality and its influence on chronic diseases, like cancer. He explains, “The immune system does not work well if vitamin D is not optimal,” emphasizing its role in cancer, where immune strength is crucial.

Recent research, including melanoma studies, indicates that vitamin D supplementation can enhance treatment responses and prolong survival in cancer patients, even with currently insufficient daily dosage recommendations.

Vitamin D also plays a significant role in heart health. Studies have linked low vitamin D levels to an elevated risk of heart disease. Those deficient in vitamin D are more likely to experience hypertension, heart failure, and strokes.

Mental health is another arena where vitamin D plays a significant role. Kimberly Parker, a licensed psychotherapist, told The Epoch Times, “There’s a clear link between low levels of vitamin D and higher incidences of depression and mood disorders.”

It also affects seasonal affective disorder, a depression variant tied to seasonal changes. “I have seen my patients have a reduction of symptoms once they started to become consistent with their vitamin D intake,” she reports.

Vitamin D’s Journey From Sunlight to Cellular Powerhouse

Vitamin D is vital for health, existing in different forms, each taking a unique path within our body. Grasping these forms is key to understanding how vitamin D functions in our system.

Once vitamin D enters our body through sun, diet, or supplements, it transforms to become active. First, it changes into calcidiol in the liver, then into calcitriol, its active form, in the kidneys. Dr. Holick clarifies, “Calcitriol is the form that our body can use to perform various functions.”

Interestingly, each form of vitamin D undergoes a similar conversion process in the body. The source of vitamin D might differ, but the pathway it takes in our bodies converges.

The conversion efficiency of vitamin D can differ. The skin’s capacity to produce vitamin D3 diminishes with age and is influenced by skin pigmentation, geographical location, and lifestyle.

Controversies in Vitamin D Testing

The routine way to measure vitamin D levels in the body is through a blood test called 25-hydroxyvitamin D. This measurement reflects vitamin D levels from sunlight, food, and supplements. The less recommended 1,25-dihydroxyvitamin D test fails to gauge vitamin D reserves, rendering it ineffective for patient monitoring.

Vitamin D blood testing has surged, ranking as Medicare’s eighth most common lab test. Market reports pegged the 2023 testing market at $677.5 million, with projections reaching $1.06 billion by 2031.

Once led by giants like Abbott, Siemens, and Quest Diagnostics, the vitamin D testing market is now seeing a surge in home testing kits from smaller companies. Dr. Holick recalls, “Years ago, I told Quest that this would be their number one seller.”

“More than 10 million vitamin D blood tests are done annually in the United States, even though these tests are not recommended by major medical organizations,” Dr. Morton Tavel, a cardiologist and specialist in internal medicine and cardiovascular disease, told The Epoch Times. He references a 2020 Virginia health system study, where 10 percent of patients underwent vitamin D tests, often without medical indication.

Beyond adults, vitamin D testing in children skyrocketed 30-fold in 15 years, as per a BMJ study, though it didn’t significantly alter low vitamin D diagnosis rates.

This increase in vitamin D testing contrasts with medical associations’ guidelines, which generally discourage routine testing in asymptomatic, low-risk individuals.

For instance, the Endocrine Society recommends screening only high-risk groups. The U.S. Preventive Services Task Force sees insufficient evidence for universal screening. Choosing Wisely also advises against testing in low-risk groups, including the general population.

Dr. Joel Finkelstein from Massachusetts General Hospital’s Bone Density Center, as reported in a Harvard Health blog, voices skepticism about the rampant vitamin D deficiency screening, deeming many checks on healthy individuals unnecessary.

“Vitamin D has been hyped massively,” he states. “We do not need to be checking the vitamin D levels of most healthy individuals.” He challenges the evolutionary need for high vitamin D, noting its limited presence in natural foods and reduced synthesis in darker skin, common in sun-rich areas.

However, many functional medicine and naturopathic doctors recommend regular vitamin D testing. The College of Naturopathic Medicine advises those in sun-poor climates to test routinely for better health maintenance.

Aligning with this view, Dr. Goodyear emphasizes the tests’ relevance, particularly regarding inflammation and chronic diseases like cancer. He told The Epoch Times, “Vitamin D will always be low in the place of significant inflammation, both acute and chronic,” advocating for regular monitoring for proper supplementation.

Dr. Goodyear draws an analogy to salmon swimming upstream against a current of inflammation, illustrating the challenges in increasing plasma vitamin D levels in such conditions. He likens this process to standard medical practices like monitoring blood pressure, emphasizing the need for a similar approach in natural therapies, “The process is to evaluate, dose, re-evaluate, and then re-dose,” he adds.

Reflecting the views of Linus Pauling, considered to be the “father of vitamin C,” Dr. Goodyear criticizes the medical oversight of pharmacokinetics and dynamics in natural therapies. He explains that physicians learn drug dosage precision but often forget that this also applies to vitamins. He advocates for a tailored approach in vitamin D therapy, moving away from a one-size-fits-all methodology.

Defining Optimal Vitamin D Levels

According to the U.S. Preventative Services Task Force, “No consensus exists on the definition of vitamin D deficiency or the optimal level of total serum 25-hydroxyvitamin.”

Some experts view 25(OH)D levels under 30 ng/mL as deficient. Common standards suggest 30-60 ng/mL as sufficient. Yet, many functional health practitioners advocate for an optimal range of 50–80 ng/mL.

Recommendations according to the National Institutes for Health (NIH):

nmol/L	ng/mL	Category
<30	<12	Deficiency
30 to <50	12 to <20	Insufficient
≥50	≥20	Adequate
>125	>50	Adverse effects

The NIH clarifies that optimal vitamin D levels are unestablished, as they “vary by stage of life, by race and ethnicity, and with each physiological measure used.”

Contrasting these guidelines, voices like Dr. Goodyear’s claim current vitamin D dose recommendations are too low. He labels the current U.S. recommended daily allowances as “woefully inadequate.”

Dr. Goodyear notes that the conventional focus on preventing rickets overlooks the broader health benefits of higher vitamin D levels. This stance argues for higher optimal ranges, implying current standards don’t fully exploit the vitamin’s health potential.

Read the full story in The Epoch Times.