In the hierarchy of vitamins, few are more important than Vitamin D. The hard part is, there are many different forms of vitamin D, and many competing beliefs on exactly how much you need to experience the numerous benefits.
To help simplify the process (and understand what you can really expect to experience from the supplement), we created this simple guide to help you better understand how to take advantage of this essential nutrient to support immune function, performance, weight loss, and general health.
What is Vitamin D? And Why Do We Need It?
Vitamin D is essential for immune function, bone health, and calcium absorption [MayoClinic]. Its main purpose is to maintain calcium and phosphorus levels in the blood.
Without these healthy levels of calcium and phosphorus, your bones would easily become brittle and break. When exposed to sunlight, your skin produces vitamin D, and vitamin D can also be found in supplements and certain foods.
Different types of Vitamin D:
- Vitamin D2 (ergocalciferol) derives from plant sources like lichen and fungi
- Vitamin D3 (cholecalciferol) derives from animal products like lanolin. It’s the one more similar to the vitamin D our bodies naturally produces from sunlight
That’s not the only difference between D2 and D3. Vitamin D3 is created in your skin when exposed to sunlight. Similarly, D2 is produced in plants as oil when exposed to UV rays.
However, these two are not identical in relation to raising vitamin D levels. Both are absorbed into our blood, but vitamin D2 is metabolized differently by the liver.
When comparing equal parts of D2 to D3, D2 yields less calcifediol than D3, meaning that vitamin D3 is more effective in increasing blood levels than D2. That is why it is recommended by medical professionals over D2. Source
But, vitamin D is not only critical for our bone health.Our body’s organs and tissues have vitamin D receptors which indicates a much greater meaning for vitamin D beyond bone health [Harvard].
Vitamin D Supplements: The Background
We know that vitamin D is essential for the functioning of human bodies. But, why did vitamin D supplementation become so popular?
One of the simplest answers comes from UV exposure: Most individuals do not readily expose themselves to sunlight. In addition, many fear sun exposure due to the increased risk of developing skin cancers.
It is recommended that one spend 15-20 minutes in the sun with 40% of their skin exposed to receive a healthy dose of vitamin D.Source
As a result, most individuals do not receive the proper amount of vitamin D. This is indicative of how common it is for an individual to have a vitamin D deficiency. It is estimated that 1 billion people across the globe have deficient levels of vitamin D.
Those who suffer from a vitamin D deficiency are at an increased risk of
- Cardiovascular disease death
- Severe asthma
- Cognitive impairment
- Type 2 Diabetes Source
- Hypertension Source
- Glucose Intolerance Source
- MS (Multiple Sclerosis) Source
Vitamin D3 Benefits: What’s Real (And What’s Not)
Real Benefits: Bone Health
The benefit of vitamin D3 comes with the improvement of bone health. It has been found that lower levels of vitamin D can lead to osteoporosis and osteomalacia (i.e. weaker, brittle bones). Therefore, supplying yourself with enough vitamin D is imperative for healthy, strong bones.
Osteoporosis is defined by the thinning of bones that result in the weakening of bones and functionality. As we have previously seen, vitamin D is essential in maintaining healthy bones.
Without this vitamin being produced in the body, calcium cannot be correctly absorbed resulting in the worsening of osteoporosis. Source
Real Benefits: Obesity
According to research conducted by PLOS Medicine from 42,000 people’s genetic information, researchers found that individuals with a predisposition for being heavier-set tended to have lower levels of vitamin D.
It is, however, important to note that genes associated with lower levels of vitamin D do not necessarily result in obesity. Source
Real Benefits: Cardiovascular Issues
A number of clinical trials have found that people with vitamin D deficiencies are at an increased risk of heart attacks, congestive heart failure, peripheral arterial disease, strokes, and cardiovascular disease [Source].
Therefore, fixing one’s deficiency can decrease the rate of those heart-related problems.
Potential Link: Multiple sclerosis
Research has indicated that maintaining health levels of vitamin D leads to the decreased risk of developing multiple sclerosis [Source], a generally degenerative disease.
And, even in the case of having multiple sclerosis, researchers have found that vitamin D may offer some benefits including:
- Lessening the severity of symptoms
- Improving a person’s quality of life
- Lengthening the progress time from relapsing-remitting multiple sclerosis to secondary-progressive phase
Research also suggests that lower levels of vitamin D lead to an increased risk of breast cancer [Source]. In its suggestion, vitamin D may be instrumental in the normal cell growth in breasts resulting in the hindering of cancer cell growth.
Vitamin D may be beneficial for other ailments, including…
- Decrease your chance of getting the flu [Source]
- Improve depression [Source]
- Treat anxiety [Source]
- Assist with healthy weight-loss [Source]
While research has been conducive to indicating other health benefits of vitamin D, there is very little research pointing to the benefits of vitamin D supplementation in decreasing the risk of Type 2 Diabetes.
The European Journal of Endocrinology conducted a recent study to determine if vitamin D3 supplementation decreased insulin sensitivity in patients who had diabetes or were at high risk. While this is encouraging, it is still one of the only studies that have found significant benefits in vitamin D supplementation.
How to Tell if You Need More Vitamin D
Firstly, what is a vitamin deficiency? To be deficient in a vitamin means that one produces lower than optimal levels of that vitamin. The optimal levels of vitamin D are between 40-80 ng/mL. However, deficient levels are identified as lower than 20 ng/mL.
Although only a medical professional can truly diagnose a vitamin D deficiency (via a blood test), there are a few general things to watch out for if you suspect a deficiency [Source]:
- Becoming sick frequently
- Fatigue and tiredness
- Bone and back pain
- Mood changes such as depression
- Slower healing of a wound
- Bone loss
- Hair loss
- Muscle Pain
Certain medications can decrease your absorption of vitamin D (like prednisone, certain blood pressure medications, and Lipitor). So, it’s very important to check in with your doctor about all the medications and supplements you take, to make sure your health regime is working efficiently for your body.
How to Get More Vitamin D3
The easiest way to increase vitamin D levels is to expose yourself to the sun more often. Again, as suggested previously, spending 15-20 minutes exposing 40% of one’s skin every day results in the production of healthy vitamin D levels.
This method, in conjunction with eating more fatty fish such as salmon, herring and sardines, canned tuna, which all contain D3, will provide more benefits.
Vitamin D Levels:
Recommended Daily Minimum Vitamin D:
- 400 IU for children up to 12 months
- 600 IU for 1-70 years of age
- 800 IU for over 70 Source
To put this in perspective:
- 3 oz of Salmon = 447 IU
- 3 oz of Canned Tuna = 154 IU
- 2 Sardines from can = 46 IU
- 3 oz of Herring = 182 IU
However, if you are a vegan, consuming fortified foods also supplies vitamin D, in the form of vitamin D2. Food to consider include:
- soy milk
- orange juice
- cereal and oatmeal
Additionally, you can find vitamin D3 in vegetarian options such as:
- egg yolks
- Cow’s milk
If your lifestyle does not allow you to receive the optimal amount of vitamin D from diet and sunlight alone, then a supplement might be beneficial.
Can You Have Too Much Vitamin D?
Although vitamin D toxicity is rare and caused only by supplementation, excessive amounts of vitamin D in your body can lead to potentially serious outcomes.
Research has shown that 4,000 IU of vitamin D per day is recommended for many benefits without side effects. If you're worried about hitting dangerous levels, research suggests you might experience negative side effects and toxicity if you consume 40,000 - 100,000 IU of vitamin D. Source, Source, Source
If you're curious about what it feels like to have too much vitamin D, some of the negative symptoms could include:
- Weak stomach
- Poor appetite
- Unplanned weight loss
- Kidney damage
- Heart rhythm issues
Vitamin D is an essential, natural way to keep your bones strong and healthy. In our modern world, most people work indoors and fear the harness of UV rays, so it’s difficult to get the optimal vitamins we need.
But, it’s simple to implement healthy change without undergoing complete lifestyle alteration.
Expose yourself daily 15-20 minutes of sunlight and implement more vitamin D induced foods in your diet and you’ll be on your way. If you feel concerned that you are deficient in any way, seek medical testing and advice from your physician and consider asking if supplementation is necessary for you.