Over the 7 years I have been learning, studying nutrition, I've had to rethink many aspects of nutrition that I thought were simple and straightforward. What we eat and even the chemicals we put on our skin have profound effects on our health, and we often underestimate how food impacts our body. One such topic where my understanding and views have evolved is vitamin D —often seen as a simple supplement with seemingly only positive effects. However, it’s not that simple. This article summarises the insights from a recent ZOE podcast featuring experts Professor Tim Spector and Dr. Federica Amati.
Photos sources: Pixabay
Vitamin D- The Sunshine Vitamin, or Something Else?
Vitamin D has been dubbed "the sunshine vitamin," playing a crucial role in maintaining health, particularly in bone growth, immune function, and reducing inflammation. One billion people globally are said to have low levels of vitamin D.
It’s no surprise that so many people reach for supplements. Governments worldwide recommend taking vitamin D pills for at least half of the year. In the UK, the suggested daily amount is 400 IU (international units), while in the US, it's 600 IU. But what if we're getting it wrong? As also pointed out in the ZOE podcast, vitamin D isn’t even technically a vitamin—it’s a steroid hormone. Our body can produce it through sunlight exposure, which differentiates it from real vitamins, such as, B and C vitamins, that we must obtain solely from food. Also, our genes determine how much vitamin D our body needs, uses- so it's not the same level for everyone.
Too Much of a Good Thing?
In recent years, concerns have arisen about people consuming excessive amounts of vitamin D, which can lead to toxicity. Some studies show that individuals taking large doses—up to 5,000 IU or more a day—are at higher risk for fractures and falls. Unlike water-soluble vitamins like vitamin C or B, excess vitamin D isn't flushed out of the body but accumulates, which can lead to nerve and muscle issues. The takeaway from the podcast was clear: overdosing on vitamin D can be harmful, and it's important to balance intake through diet, sun exposure, and supplements carefully.
The real confusion lies in the recommendations themselves. Blood levels of vitamin D vary widely from country to country, and experts, including Professor Spector, question whether these guidelines have become inflated without sufficient evidence. For example, in the US, a blood level of 28 ng/mL is deemed optimal, while in the UK, it's 12 ng/mL. Yet there's no conclusive proof that higher levels are better. As a result, many people are supplementing without understanding whether and how much they need it.
How Do We Get Vitamin D?
Vitamin D can be obtained from three sources: sunlight, food, and supplements. The body is designed to produce enough vitamin D from sun exposure, but lifestyle factors (spending a lot of your daily life indoors) and geographical location can limit this. Foods such as oily fish (herring, mackerel), mushrooms, eggs and dairy products are good sources of vitamin D, but they are rarely enough to meet the daily requirement.
It's critical to remember that getting outside and exposing your skin to the sun on a daily basis is the best you can do—even for just 15 to 20 minutes a day without sunscreen during the non-peak UV hours (before 10am and after 4pm)—can naturally boost your needed vitamin D levels.
Supplementing: Who Needs It?
Certain groups do benefit from vitamin D supplements, particularly those with health conditions such as Crohn's disease, multiple sclerosis or cancer. Trials like the VITAL study have shown improved outcomes in patients already diagnosed with certain diseases when taking vitamin D. However, this doesn’t mean the general population should rush to the store for high-dose D-vitamin supplements.
People living in the Northern Hemisphere often experience lower levels of sunlight during the winter months due to the angle of the sun and shorter daylight hours, which significantly reduces their body’s ability to produce vitamin D. As a result, individuals in these regions can be at risk of vitamin D deficiency. So supplementing with vitamin D during the winter months can help to maintain adequate levels. But it's best to get your
blood levels checked first (your family doctor can order it or you can go to your closest lab yourself (like Synlab in Estonia) and then determine with your doctor if, how much and for how long you should supplement. Vitamin D deficiency is rare in healthy individuals with an active outdoor lifestyle and balanced diet, but for those at risk—such as older adults or people with limited sun exposure—supplementation could be beneficial.
Conclusion: Reevaluate Your Supplementation
In a world where we're often looking for quick fixes, vitamin D supplements might seem like an easy way to boost your health. However, as highlighted in the ZOE podcast, it’s vital to remember that vitamin D is not a cure-all and over-supplementing can lead to toxicity. It's best to focus on getting your vitamin D from regular exposure to the sun during non-peak UV hours, from a balanced diet and supplementing only when needed.
For those curious about the latest science behind vitamin D, I encourage you to check out the full ZOE podcast episode with Professor Tim Spector and Dr. Federica Amati, where they dive deep into the complexities of this so-called “vitamin.”
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If you are someone looking to improve your nutrition, lose or gain weight following a healthy balanced diet, but don't know where to start, do reach out to me for nutrition counseling at info@katrinpeo.com.
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