Vitamin D has long been referred to as “the sunshine vitamin,” and with good reason. The ultraviolet rays of the sun are tasked with providing people with the majority of the vitamin D they need for good health. But a recent decline in outdoor activity rates, combined with inadequate vitamin D intake in food, have resulted in a rise in vitamin D deficiency across the globe.
Vitamin D is a crucial part of good health. In this guide, you’ll find everything you need to know about vitamin D, including:
- What vitamin D does in the body, including symptoms of deficiency
- Major research-backed benefits
- Where to find vitamin D in foods and elsewhere
- How to determine the proper dose for you
- Safety information if you’re supplementing with vitamin D
What Does Vitamin D Do?
Contrary to its name, vitamin D is not actually a vitamin. It is a prohormone — a precursor to a hormone — and it is present it nearly every tissue in our body. This prohormone is fat soluble. It can be found in some foods, through vitamin supplementation, and in the rays of the sun (hence its nickname).
There are two main types of vitamin D. Both of these are naturally occurring in the presence of the sun’s ultraviolet-B (UVB) rays.
- D2 (ergocalciferol): Produced in plants and fungi
- D3 (cholecalciferol): Produced by animals, including humans
Other than what produces them, these two types of vitamin D do not differ in any major way. The body uses each form in a similar fashion. The small intestine is responsible for absorbing and assimilating vitamin D. It does its job better in the presence of fat. Fat is not required to use vitamin D, but it does help the small intestine to work more efficiently.
One of the things that is also different about vitamin D as compared to other vitamins is that age or body condition does not affect how we absorb it. We are just as good as absorbing vitamin D when we are young and fit as when we get older and are carrying a few extra pounds.
Further, vitamin D is a crucial part of our diet. It helps us to absorb calcium and phosphorous to build strong bones. This is one of the reasons that vitamin D is added to milk. It also helps to bolster healthy immune system function and can protect against many diseases, including type 1 diabetes.
Research is now beginning to uncover a host of other benefits. These include vitamin D’s ability to:
- Help ease pain
- Regulate mood
- Help with sleep issues
- Shore up a weakened or compromised immune system
With just a few exceptions, vitamin D is well-tolerated in the body. It is safe and offers very few risks or side effects. Supplementing a regular diet with sunshine and a vitamin D pill may be a great way to improve general overall health. It can also combat a growing global problem: vitamin D deficiency.
The symptoms of a vitamin D deficiency
Nearly 42% of adults in the U.S. do not get enough vitamin D through exposure to the sun, food, or supplementation. In children, an estimated 10% are vitamin D deficient. An estimated 60% more are ingesting suboptimal levels of vitamin D daily.
The risk is higher for people with the following circumstances or conditions:
- Lower levels of education
- Overall poor health
- Location relative to the equator (less sunshine equals higher risk)
- Conditions that impact absorption (e.g., Crohn’s or celiac disease)
- Diet with few animal products (i.e., vegans or vegetarians)
People with darker skin (including those living close to the equator) are at high risk of vitamin D deficiency. The same melanin in their skin that provides protection from skin cancer can also prevent the absorption of sun-based vitamin D. Finally, people who do not regularly consume milk that is fortified with vitamin D are also at risk.
So, what are the symptoms of vitamin D deficiency? Symptoms can quickly progress from mild to serious disease and can include:
- Extreme fatigue and general tiredness
- Experiencing regular infections and illness
- Pain in the bones
- Pain or chronic soreness in the back
- Slow-healing wounds
- Bone loss
- Muscle pain
- Confusion or disorientation
- Hair loss
Children with prolonged vitamin D deficiency can develop rickets. Babies of nursing mothers with vitamin D may also develop this condition.
Most people who have vitamin D deficiency are not even aware of it. The symptoms are subtle and non-specific. Many healthcare providers may not even think to test for it.
The good news? Vitamin D deficiency is remarkably easy to remedy, and the benefits of restoring the body to balance are ample. Let’s look at those benefits in more detail.
Major Vitamin D Benefits
It’s crucial to maintain the appropriate level of vitamin D in your body. Vitamin D makes for strong bones and overall good health. It also has some surprising benefits for pain, depression, anxiety, sleep disorders, and immune health.
Vitamin D for pain
Could a simple vitamin supplement or extra 20 minutes in the sun a few times a week really change life with chronic pain?
More research is showing that adding vitamin D for pain might be one of the missing links in pain management.
- A 2017 study noted that observational studies seemed to indicate that low levels of vitamin D were associated with both more pain and higher doses of opioids to manage it
- Another 2015 study noted a statistically significant decline in pain score measurements when vitamin D supplementation was given to patients with chronic musculoskeletal pain
- Adding vitamin D to palliative care for cancer patients reduced pain, improved well-being, and reduced infections
- A preliminary study in 2021 indicated that vitamin D reduced pain and helped to prevent temporomandibular joint disease (TMD)
- Vitamin D supplementation was linked to pain relief in patients with neuropathic pain caused by type 2 diabetes
Vitamin D was also examined in a major review of studies that looked at the role of nutraceuticals in the treatment of chronic pain. Vitamin D deficiency was clearly linked to pain in osteoporosis as well as other kinds of pain (e.g., fibromyalgia and rheumatoid arthritis).
The research seems to indicate that at a baseline, adequate vitamin D is crucial in pain management. Some studies recommend additional supplementation to achieve pain relief.
Vitamin D for depression
Sifting through the research regarding vitamin D for depression is challenging.
There already exists a strong connection between lack of sunshine and depression. Seasonal affective disorder (SAD) is caused by changing seasons and waning sunlight, with symptoms of depression and fatigue. Adding vitamin D can help increase the production of serotonin in the brain while decreasing inflammation. These are two keys to help treat depression.
But could the symptoms of depression — either due to SAD or clinical depression — be caused by lack of vitamin D?
A 2020 review of studies found a relationship between depression and vitamin D deficiency, but the directionality (which came first) was unclear. Two factors might indicate that depression is caused by vitamin D deficiency. First, there are ample vitamin D receptors in the area of the brain that regulates mood. Vitamin D also plays a role in inflammation — one of the key features of depression in the brain.
However, another long-term study on the effects of vitamin D supplementation to decrease or reduce the risk of depression found no difference between a placebo and vitamin D. Research into this complex relationship is ongoing.
While low vitamin D levels appear to be a common factor among those who suffer from depression, it’s not clear that simply adding a supplement will treat depression. This was especially true for those who are not vitamin D deficient.
A final thing to consider when looking at vitamin D and depression: circumstances.
For example, the COVID-19 pandemic sent researchers back into the lab just as people across the globe went on lockdown. Depressive symptoms in the U.S. increased threefold during the lockdowns. Ample research conducted during the pandemic appears to indicate that lack of vitamin D from sun and food sources have contributed to an increase in depressive symptoms. This includes an increased inability to deal with stress.
Vitamin D for anxiety
Another potential benefit of vitamin D comes in the form of helping to manage anxiety.
Calcidiol is a by-product of vitamin D breakdown. In people with anxiety and depression, low levels of calcidiol indicated that there was an inadequate level of vitamin D. And, as with depression, low serotonin and high inflammation levels increase the likelihood of anxiety in a broad range of people.
But does adding vitamin D for anxiety help treat it? Recent studies appear to indicate that it could:
- A 2020 study found that in patients with both anxiety and depression, depression remained largely the same as with a placebo but anxiety levels dropped dramatically after receiving a vitamin D serum for six months
- Vitamin D was also credited with a decrease in negative emotions related to both anxiety and depression
- In people with generalized anxiety disorder, vitamin D helped reduce the severity of symptoms
- A study of women with diabetes found their mood improved, anxiety diminished, and inflammation reduced when supplemented with vitamin D for four months
- Children receiving dialysis are more likely to have low vitamin D levels that lead to anxiety
Anxiety can be a debilitating, life-altering condition. Supplementation with vitamin D can be one tool for helping treat this challenging condition.
Vitamin D for sleep
Since vitamin D is found in nearly every tissue of the body, and it regulates the production of feel-good hormones and the immune system, it stands to reason that vitamin D deficiency could affect sleep.
A systematic review in 2020 looked at sleep disorders, PTSD, and depression during and after pregnancy. It found a direct correlation between low vitamin D levels and an increase in sleep disorders and PTSD.
An earlier systematic review of studies in 2018 laid the groundwork for the connection between low levels of vitamin D and poor sleep. Researchers looked at nine studies with almost 9,400 participants and found that vitamin D deficiency:
- Significantly increased the risk of sleep disorders
- Was associated with poor sleep quality
- Caused short sleep duration and sleepiness
- Could significantly increase the risk of unhealthy sleep
Vitamin D for sleep is still a big area of exploration in science. Researchers agree that vitamin D plays a role in healthy (and unhealthy) sleep. But they also agree that there is a need for more interventional, scientifically-valid studies.
Vitamin D for immune health
Vitamin D has a direct effect on our immune systems. As expressed on the immune cells, vitamin D can help modulate our immune system’s response. This connection is very clear, and the lack of vitamin D results in the heightened possibility of any kind of infection and an increase in autoimmunity disorders.
In some astonishing research specific to COVID-19, it appears that low vitamin D levels are associated with an increased risk of COVID-19 infection.
But even before COVID changed the way we looked at our immune systems, a large-scale, long-term study found that supplementing with vitamin D prevented respiratory tract infections, especially for people who started with a deficiency. Vitamin D works to protect respiratory health and could prevent infection in two ways:
- It supports the production of antimicrobial peptides in the epithelium of the respiratory system
- It reduces the inflammatory response
The second factor is not just beneficial in the fight against COVID. Reducing the body’s inflammatory response is associated with:
- An overall reduction in disease
- Decreased risk of mortality
- Increased quality of life
In terms of COVID-19, the best protection against this disease remains vaccination. Not only does it protect the vaccinated person, but it also prevents the spread of the virus to others.
There’s no arguing the science. COVID-19 vaccinations are still the best option to protect yourself and your family against severe infection and even death. Vitamin D can’t replace that. However, maintaining the proper levels of vitamin D in your body is a good way to support your overall health, year-round. Talk to your doctor about your options for vaccination, then look into testing your vitamin D levels to ensure you have adequate support there, too.
Other vitamin D research
When something as simple and safe as a supplemental vitamin shows such great promise, researchers make other connections as they study its effects.
A few of the most recent research findings include the following studies.
Adding a simple vitamin D screening when testing for colorectal cancer (and then supplementing those with deficiencies) may protect against colorectal cancer in people under 50.
In animal studies, vitamin D deficiency increased the risk of addiction to both opioids and ultraviolet rays. Researchers found that supplementation restored the balance.
Researchers in Germany found that vitamin D supplementation for all Germans over 50 could result in up to 30,000 fewer cancer deaths per year and an additional 300,000 years of life gained. They also calculated an annual savings in healthcare costs of the equivalent of $300 million USD.
A study of female outdoor workers over 50 found that they had a reduced chance of breast cancer. This observational study found that those working outside for 20 or more years had a 17% lower risk of a breast cancer diagnosis. It’s worth noting that this is just a preliminary study.
There is so much more to learn about vitamin D and the potential it holds. While it can be difficult to perform diet-related research with its myriad of complexities, vitamin D in particular promises to provide real benefits to our bodies and overall health.
If you’re interested in improving your vitamin D levels, keep reading to learn about the best sources for getting it – in food or supplement form.
What Are The Best Vitamin D Sources?
Even though the body can use both types of vitamin D, the most recommended form is D3. This is the type that your body produces by itself when exposed to sunlight. It is also the same type that is found in animal proteins.
Let’s look at how to get vitamin D in the foods you eat and in supplements.
What foods have vitamin D?
Even though humans can naturally produce vitamin D, few foods are naturally rich in this vitamin. Most food-based vitamin D is added to foods (labeled as “fortified”). The majority of your dietary vitamin D will come from fortified food.
For omnivores, the best way to get vitamin D is through fatty fish and fish liver oils. There are also small amounts of vitamin D in egg yolks, cheese, and beef liver. Certain cultivated mushrooms also have vitamin D as well. These mushrooms are exposed to high amounts of ultraviolet light that causes them to produce vitamin D.
Oily fish is the most powerful source of vitamin D in food. If you do eat fish, make sure to reference a program like Seafood Watch which can help you find ecologically-friendly options.
For example, salmon is a widely available and popular fatty fish that also happens to be a good source of vitamin D. One 3.5 ounce serving of Atlantic salmon contains 66% of your daily value. But sustainably sourced wild salmon goes even further. One 3.5 ounce serving of wild caught salmon provides 124% of your daily value of vitamin D. If you have a choice, choose wild, but don’t pass up farmed salmon.
Two other oily fish, herring and sardines, are less commonly eaten in the United States but provide another great source of vitamin D. A 3.5 ounce serving of fresh Atlanta herring provides 27% of your recommended daily allowance. Canned sardines provide just slightly less at 22%.
Meatier fishes like halibut and mackerel provide nearly double that amount.
Want something quick and easy? Cod liver oil is a great option. It can be taken as a supplement or by the teaspoon in a liquid. One teaspoon of cod liver oil gives you a whopping 56% of your recommended daily allowance. Cod liver oil also offers plenty of vitamin A, at 150% of the recommended daily allowance for per teaspoon. Another benefit of cod liver oil is that it is high in omega-3 fatty acids. If you take this form of vitamin D supplementation, be careful not to take too much. Vitamin A can be toxic in high amounts.
Canned tuna is another convenient way to add vitamin D to your diet. It’s easy to store, and it is a versatile pantry staple. One serving of tuna provides 34% of your daily recommended allowance. Keep in mind that pregnant women should avoid tuna as it contains methylmercury. This toxin, found in many species of fish, can cause serious health problems if it builds up in your body. Choose light tuna and eat no more than six ounces per week.
Fortified foods are great for vegetarians or vegans. They are also a good option if you do not like the taste of fish. Fortified dairy and non-dairy milk can be a good source of vitamin D. Each provides between 10-22% of your recommended daily allowance.
If you’re not a milk drinker, orange juice is another option. This is an especially good choice for people who are lactose intolerant (an estimated 75% of the world) or have a milk allergy (another 2-3% across the globe).
Choosing fortified orange juice not only provides vitamin D, but can also provide added calcium. Vitamin D helps calcium to be absorbed into the body. One cup of orange juice with your breakfast starts your day with 12% of your recommended daily allowance of vitamin D. Add a bowl of fortified cereal or oatmeal, and you’ll be well on your way to getting the vitamin D you need.
Vegetarians and vegans may struggle to get enough vitamin D in their food alone. Vegetables are not a source of vitamin D, nor are nuts and seeds. Some options for those on a plant-based diet, though, include:
- Fortified tofu
- Fortified soy yogurt
- Beans, including white, black, lima, pinto, calico, and kidney beans
- Split peas
- Shitake mushrooms
The volume of vitamin D from these sources is not enough to meet the recommended daily allowance. Talk to your doctor about possible solutions if animal protein is not part of your diet.
Other natural sources of vitamin D
Sensible daily exposure to sunlight is one of the best ways to boost natural vitamin D production. Take five to ten minutes, two or three times a week, to expose bare skin to sunlight. This might be a quick walk with bare arms during lunch or a morning cup of coffee outside.
Because vitamin D breaks down quickly, you’ll need to be consistent with your exposure. But consider this: not only are you making natural vitamin D, but you are also reaping the ample benefits of time spent outdoors. It’s a win-win.
Keep in mind that there are some people with an elevated risk of skin cancer. Extra time outdoors may not be advised. Wearing sunscreen helps minimize this risk, but it also blocks the ultraviolet rays that prompt the production of vitamin D. One option is to spend time outside in the early morning and evening. The sun is not as intense at this time, and it may be safer to venture out without sunscreen.
As always, if you have concerns, talk to your doctor.
Using vitamin D supplements
Even though food and sunlight are the most organic ways to get your recommended daily allowance of vitamin D, supplements might be the only option for people with restricted diets or limited ability to access sunlight.
And for people taking higher doses of vitamin D under a doctor’s supervision, vitamin D supplements are the only way to get the required amount. Keep reading to learn more about how to find and choose the right supplements for you.
How To Take Vitamin D Supplements
Tapping into the benefits of vitamin D is all about making the effort to include the appropriate daily amount into your life. If you aren’t sure whether or not you need more vitamin D, talk to your doctor about getting a test to measure your levels.
How to get more vitamin D
In a perfect world, everyone would have adequate access to sunshine in bodies that readily absorbed ample amounts of daily vitamin D. While this is the reality for some, unexpected global lockdowns, illnesses, and the general trials of daily living can sometimes compromise our ability to get the amounts that we need. Further, some people may need it in the darker winter months when there are fewer hours of sunlight, and not in the summer.
Additionally, vitamin D is scarce in foods and breaks down quickly in the body. If we need higher levels, the challenge rises accordingly.
There’s no sense in dwelling on a “perfect” scenario. Whatever helps you get exactly the vitamin D your body needs is a good solution. Sometimes that’s more sunlight, sometimes it’s more fortified foods, and sometimes it’s a supplement. These are all great options to help you maintain good health.
How to choose a supplement
It’s always important to work with your doctor when choosing the vitamin D supplement that’s the best one for you. They’ll be able to point to reputable brands and types of supplements that would work best for you.
When you’re thinking about the type of vitamin D, D3 is the natural type produced by your body. In general, adding more nutrients to your diet with D3 is preferred because it’s the more potent and recognizable type in the body.
When it comes to the best form of vitamin D, you have plenty of options. You can choose a tablet, a pill, a liquid, or dissolvable powders. If you struggle to swallow pills, vitamin D powder might be a good choice for you. Not only is it easier to take, but it can also be added to drinks or food during meals.
Which form you choose is largely a matter of preference. A small-scale study found no significant differences between the use of liquids or tablets and absorption by the body. Further, finding the option that works best for you and your daily routine is key. Ongoing compliance and daily use are the best ways to realize the benefits from your vitamin D supplementation.
Finally, another relatively new option is vitamin D-fortified skin care products, like lotions or serums. These might be the best option for people who struggle to absorb vitamin D through exposure to sun or through diet. People with this challenge include those faced with the following conditions:
- Crohn’s disease
- Celiac disease
- Cystic fibrosis
But because these products are relatively new, research on them is new as well. A very small study of vitamin D-fortified skin care products suggests, but does not prove, that vitamin D3 is truly safely and effectively absorbed through the skin. No side effects were noted in this study. At the very least vitamin D-fortified skin care products will make for softer skin.
How much vitamin D should I take daily?
To determine how much vitamin D you should take daily, talk to your doctor. They can advise you on the proper amount for you based on medications, underlying risks, and pre-existing conditions that may benefit from an increased dose.
Generally speaking, the recommended daily amount (RDA) of vitamin D is as follows:
- Children to 12 months: 400 international units (IU)
- People aged one to 70: 600 IU
- People 70 and older: 800 IU
This amount can be achieved mostly through diet, but a supplement can help, too.
When should I take vitamin D?
When you take vitamin D can also affect your body’s response. Because vitamin D is fat soluble, taking it with a large meal that includes healthy fats like olive oil, avocados, or nuts can help your body reap more of the benefits. Avoid trans fats, like those common in fried or packaged foods.
Additionally, the time of day actually does matter, too. A small study in 2013 found that vitamin D may reduce the secretion of melatonin. This is the hormone that naturally helps us sleep. Taking a supplement too late in the day could actually cause poor sleep.
Some people find that taking supplements with breakfast helps them to remember to take them and encourages them to start the day with a healthy meal. Consistency is key, so develop a plan that works for you and stick with it.
Can I take too much vitamin D?
While the benefits of getting adequate vitamin D are many, there is a risk of taking too much. The Journal of the American Medical Association (JAMA) published a research letter in 2020 indicating that there has been a nearly 3% increase in people taking unsafe amounts of vitamin D (more than 4,000 international units (IU) per day) in the period from 1999 to 2014. In that same time, the number of people taking 1,000 IU or more a day increased by 18%.
Dr. JoAnn E. Manson, the Michael and Lee Bell Professor of Women’s Health at Harvard Medical School, lists the potential side effects or risks from such dramatic doses of this potentially beneficial vitamin:
- A 2010 study published by JAMA said that taking high amount of vitamin D is associated with an elevated risk of falls and fractures
- Too much vitamin D can lead to hypercalcemia (too much calcium build-up in the blood, with a risk of deposits in the arteries or soft tissues)
- A higher risk of kidney stones in older women
- The potential to be toxic at extremely high doses
The warning signs of overdose include nausea, vomiting, and weakness. You might also experience stomach pain, diarrhea, or constipation. Long-term, excessive vitamin D supplementation can lead to bone loss and kidney failure.
The good news is that it is virtually impossible to overdose on vitamin D included in foods or by sunbathing. The research shows that supplements are the primary cause of overdose and potential toxicity.
If you do experience symptoms of vitamin D overdose, stop taking supplements immediately and call your doctor. Because of these issues, it’s also important to talk to your doctor to ensure that you both have a deficiency that needs to be managed and the best amount to use for your body.
Does vitamin D interact with other medications?
It’s important to talk to your doctor before adding vitamin D if you are taking any of the following medications:
- Aluminum-containing phosphate binders
- Phenobarbital and phenytoin
- Cytochrome P-450 3A4 (CYP3A4) substrates
- Thiazide diuretics
- Stimulant laxatives
These medications can interact in various ways with vitamin D. This includes limiting the body’s ability to absorb it and resulting in excessive calcium in the blood.
How To Get Started With Vitamin D
To get started with vitamin D supplements, keep in mind that vitamins often need other vitamins to work well. They depend on each other, and sometimes providing more of one means you’ll need additional of the others, too.
For example, some researchers believe that fat soluble vitamins work together. Make sure your vitamin A and vitamin K intake is keeping up with your vitamin D supplementation.
Magnesium, a mineral that controls over three hundred of the body’s functions, is often low among people across the globe. While you are supplementing vitamin D, make sure you’re getting enough magnesium, too.
Getting started with vitamin D will likely be just one step on your journey to wellness. Whether you’re supplementing a minor vitamin deficiency or treating a major health condition, it’s important to work with your doctor to develop a personal, individualized plan of treatment. This might include not only vitamin supplementation, but also other complementary therapies such as acupuncture, chiropractic, and massage.
Managing your health in a way that looks at the entire body system, rather than a collection of symptoms, is the best way to approach wellness.
Taking a holistic approach with vitamin D supplementation means taking the time to evaluate your overall health and goals. This is a great way to improve all aspects of your life, even when managing complicated conditions such as chronic pain or mood and sleep disorders.
If you’re suffering from chronic conditions, like chronic pain, in Arizona, we can help. Contact Arizona Pain to learn more about treating your chronic pain.