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Vitamin D: solving the problem of "darkness at noon"

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For years, we’ve heard that Vitamin D is crucial to health. It’s added to everything from orange juice to infant formula, and with a role in everything from immune and skin health to bone density, you can’t really argue against Vitamin D benefits. Yet for many of us seeking health, Vitamin D is also a source of confusion.

For one thing, our bodies synthesize Vitamin D from the sun, but we know that UVB light used in this conversion also leads to the development of skin cancer. It’s a phenomenon researchers have referred to “darkness at noon,” because protecting ourselves from UVB means blocking our body’s main pathway for synthesizing Vitamin D3.

Vitamin D is a crucial nutrient that’s worth seeking out. That’s why we added 100% of your recommended daily value of Vitamin D to The Base Layer and why we're confident it belongs there.

In this article, we’re going to attempt to clear up the confusion around Vitamin D and sun exposure and explain why we think the dose of Vitamin D in The Base Layer is still a worthwhile part of your regular health routine.

Vitamin D benefits: do we even need more D?

Vitamin D deficiency affects an estimated 1 billion people worldwide. Americans, in particular, seem to be chronically low in this essential nutrient, though more research in this area is needed.

Those numbers are problematic because Vitamin D benefits our bone health, immune system health, calcium absorption, and a host of other important biological processes in our body.

In fact, Vitamin D is one of the best supported supplemental nutrients in the scientific literature. Other emerging areas of research suggest the Vitamin D is important for everything from cardiovascular and metabolic health to cancer prevention to healthy brain functioning.

So, does that mean we need to take more Vitamin D? 

Over the past few months, a newly published meta-study and reporting surrounding it have thrown this idea into question. One article published in Vox declared “Millions of Americans take Vitamin D. Most should just stop.” Pretty stirring stuff! But further examination of the article does not support this sweeping headline.  

The meta-analysis addressed in this article, published in the journal Lancet Endocrinology and Diabetes, only looked at the ability of Vitamin D to reduce the risk of bone fracture or changes in bone density. The outcomes here are narrow measurements of bone health later in life and certainly don’t say much about the multitude of other ways Vitamin D works in the body.

Furthermore, most of the studies included in the Lancet article examined the effect of adding Vitamin D in women aged 65 and older, and the study durations were less than one year.  Hence, these studies were looking at intervening in an older age group over a short period of time. It’s not surprising that the effects may not be seen.

For example, one may need adequate Vitamin D levels over a lifetime to maintain bone health into old age. Furthermore, only four of the 72 trials analyzed that reported serum Vitamin D levels reported using a study population who had Vitamin D levels of less than 25 nmol/L, which is considered a true vitamin deficiency.

Despite the constraints of studying the effects of Vitamin D supplementation in the elderly, other meta-analyses in these populations have indicated benefit. For example, one of the most rigorous groups to conduct meta-analyses showed that over 56 trials which included 95,286 participants, provided evidence that Vitamin D supplementation decreases all-cause mortality in the elderly. In this analysis, the mean duration of supplementation is 4.4 years—quite a bit longer than the study which prompted the media to warn against Vitamin D supplementation, but still too little time to draw such sweeping conclusions.

In contrast to the narrow outcome measurement of fractures, when expanding the concept of Vitamin D to include broader health measurements, such as the likelihood of death, a potential benefit was detected. While the likelihood of dying may seem like a dramatic way to investigate nutrition, it’s actually a strong criterion because of how broad it is - by definition, it encompasses so many other health conditions we care about.

Both of these meta-analyses, one in the positive direction and one in the negative, are severely limited by the fact that they are studying short-term supplementation in elderly populations which tend to be less healthy and have more health problems.

Conducting research on vitamins and health outcomes is a very tricky business. In an ideal world, you would randomize young people to either receive Vitamin D supplementation or not, and their health outcomes would be tracked into old age.

Since this is impossible, we have to rely on less than ideal study designs to give us information. While that information is very helpful, we also must take it in context, understanding the limitations of the experimental design.

Given all of the complexity of the data, how should we approach Vitamin D? At Sundaily, we believe Vitamin D benefits are worth seeking, so we're confident it belongs in The Base Layer. That decision was guided by the recommended guidelines from groups whose job it is to make sense of the research, such as the Institute of Medicine and National Institutes of Health (NIH).

How can we safely get Vitamin D?

According to the NIH, using a serum vitamin D concentration of 50nmol/L or higher is a threshold sufficient to cover the health needs of 97.5% of the population. The recommended daily allowances associated with this range from 600-800 IU for adults, depending on the age group.

Like most things in biology, numbers that are too low (Vitamin D deficiency) or too high (Vitamin D toxicity) can be bad, with the goal of being somewhere in the middle. Because of this, the NIH conservatively recommends an upper limit of 4,000 IU per day for adults, a dose five times higher than what is in a one-gummy serving of The Base Layer (800 IU).

Sunscreen does get in the way of Vitamin D synthesis. When our skin is exposed to the sun, it starts the process of creating Vitamin D3 within our bodies. When sunscreen's part of the equation, this gets harder since there's less light getting to our skin.

how vitamin d is converted in our bodies

2007 study found that even minuscule amounts of SPF-15 sunscreen can impede the formation of Vitamin D3 building blocks, which our bodies make into Vitamin D3. This creates an interesting conundrum since conventional sunscreens are blocking mainly the UVB part (290–320 nm) of light which matches the action spectrum of the Vitamin D synthesis in the skin.

Since we know that fully protecting ourselves from sun damage will likely impede our body’s ability to synthesize Vitamin D from sunlight, it’s smart to turn to other sources to make sure we meet recommended levels.

Whole food sources of Vitamin D may provide some of our recommended daily allowances. Foods like mushrooms, dairy, egg yolks, and fatty cold-water fish are all rich in Vitamin D. However, it’s hard to determine just how much you’re getting from these sources. For instance, according to the FDA’s database, a 100g serving of sockeye salmon contains 563 IU of Vitamin D, a number that closes in on an adult’s RDA. But a 2009 study found these numbers actually vary wildly.

That’s why Vitamin D supplementation is a worthy alternative - it’s a predictable way to get the right amount of a key nutrient.

Choosing to supplement with a vegan Vitamin D option like the one found in The Base Layer solves the conundrum of “darkness at noon.” Our formulation includes the exact amount currently recommended for adults by the National Institutes of Health and gives you the antioxidant benefits of Polypodium leucotomos extract, to boot.

As always, before starting any supplement, Vitamin D included, you should discuss this with your doctor.

Solving the “darkness at noon” problem

The Base Layer makes solving the “darkness at noon” paradox simple. With a monthly subscription, you can make sure you’re supporting healthy Vitamin D levels and helping to protect your skin from environmental stressors at the same time. Subscribe today!

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