Globally, vitamin D deficiency affects approximately one billion people.
There’s a good chance you’re dealing with low vitamin D, especially if you live in a cloudy location, have a darker skin tone (melanin reduces the body’s ability to absorb vitamin D from the sun), or have a health condition that prevents vitamin D absorption (such as liver disease or Crohn’s disease).
Do you suspect you’re deficient in vitamin D? If so, this guide answers all your most pressing questions, from vitamin D’s benefits to how you can maximize absorption.
What Is Vitamin D?
Vitamin D is also known as calciferol. It’s a fat-soluble vitamin that can be obtained through food, supplements, or sun exposure (when the sun’s ultraviolet rays hit the skin, vitamin D synthesis is triggered).
Whether it comes from the sun or food, vitamin D is biologically inert. That means it doesn’t cause a reaction immediately after it's introduced to the body. It must first go through two hydroxylation processes:
- First hydroxylation: Occurs in the liver and converts vitamin D to calcidiol (25-hydroxy vitamin D)
- Second hydroxylation: Occurs in the kidneys and forms calcitriol (1,25-dihydroxy vitamin D), which is physiologically active
The Recommended Dietary Allowance or RDA of vitamin D is 600 international units (15 micrograms) per day for men and women aged 19-69. For adults aged 70 and up, the recommendation increases to 800 international units or 20 micrograms per day.
Vitamin D2 vs. D3
If you’ve ever shopped for vitamin D supplements, you’ve likely seen some products labeled as “Vitamin D2” and others labeled as “Vitamin D3.” What’s the difference between these two options?
Vitamin D2 (also known as ergocalciferol) naturally occurs in some mushrooms (specifically those that grow in UV light). It’s also added to vitamin-D-fortified foods like cereal because it is less expensive to produce.
Vitamin D3 (also known as cholecalciferol) is found in animal products like fatty fish (such as salmon), egg yolks, liver, and butter. A vegan-friendly form of vitamin D3 can also be extracted from lichens, organisms that act as symbiotic partners between fungi and algae.
Between vitamin D2 and D3, D3 is more bioavailable and better absorbed in the body. In other words, if you want to see the most significant benefits from vitamin D, you should look for products that specifically contain vitamin D3.
Vitamin D Health Benefits
Vitamin D assists with many different processes in the body. When you meet your daily vitamin D recommendation, you support your body in the following ways:
- Reduced risk of heart disease, multiple sclerosis, and autoimmune diseases like rheumatoid arthritis and type 1 diabetes
- Better mood regulation and a reduced risk of depression
- Improved calcium absorption and stronger, healthier bones (and a reduced risk of osteoporosis)
If you’re struggling with vitamin D deficiency, you might not notice symptoms right away.
However, many symptoms are associated with low calcium levels (hypocalcemia). Hypocalcemia can cause issues like bone fragility, fatigue, muscle twitches, muscle weakness, and joint stiffness.
How to Maximize Vitamin D Absorption
To experience the many health benefits of vitamin D, you must take steps to support absorption. Here are some tips that will help you maximize absorption and get the most out of your vitamin D intake, whether it comes from the sun, food, or supplements:
Get Enough VVitamin C, Vitamin K, Zinc, and Magnesium
Several vitamins and minerals assist with vitamin D absorption, including vitamin C, vitamin K, zinc, and magnesium.
Vitamin C influences 125 D3 hydroxylase, the enzyme responsible for vitamin D conversion. Without sufficient vitamin C, your body will struggle to utilize the vitamin D you consume.
Vitamin K is responsible for shuttling calcium into the bones. Without sufficient vitamin K, your bones won’t get stronger from the vitamin D you take in.
Zinc helps vitamin D function within the cells. Conversely, adequate vitamin D levels can also improve zinc levels in the body.
Magnesium assists with vitamin D activation. The enzymes required to metabolize vitamin D also require magnesium to function correctly.
Consume Vitamin D with Fat
Vitamin D is a fat-soluble vitamin. That means it must be packaged with fat before it can be absorbed from the digestive tract.
Because of its fat-soluble nature, many experts recommend consuming vitamin D supplements with a fat source to aid in absorption. It also helps to take vitamin D with a primary meal of the day (breakfast, lunch, or dinner).
Manage Stress Effectively
Chronic stress can contribute to vitamin D deficiency thanks to the stress hormone cortisol. Cortisol interferes with vitamin D absorption (and the absorption of other vital nutrients).
If you struggle with chronic stress, you increase your risk of low vitamin D levels, as well as other health conditions like headaches, digestive problems, and elevated blood pressure.
You can’t avoid stress altogether, but you can take steps to manage your stress more effectively.
Consider practices like meditation or yoga to combat stress and improve overall health and wellness. Spending time outdoors is also helpful for those dealing with elevated stress (and it also gives you a chance to soak up the sun and boost your vitamin D levels).
Search for Quality Vitamin D Supplements
Supplementing with vitamin D can help you fill in the gaps in your diet or compensate for a lack of sunshine in your area. However, make sure you’re choosing high-quality vitamin D products.
Start by searching for supplements that specifically contain vitamin D3 for maximum absorption. It also helps if the supplement contains other beneficial vitamins and minerals that aid in vitamin d absorption, such as zinc and vitamin C.
Look for products that come with a money-back guarantee, too. That way, if you’re not satisfied for any reason, you can get a refund easily.
Get the Most Out of Vitamin D’s Health Benefits with Substance
From increasing your intake of other beneficial nutrients to managing your stress effectively, you can take numerous steps to get the most out of vitamin D’s many health benefits.
A good starting point for those looking to boost their vitamin D levels is to consume a high-quality vitamin D supplement, like SUbstance’s Vitamin D3. It’s vegan-friendly, made in the USA, and free from GMOs.