How Much Vitamin D3 Should I Take Each Day?
How much time are you spending outside in the sunshine each day? If you're like many of us, it's probably not enough - which may lead to a deficiency of the "sunshine vitamin," vitamin D.
Your body can produce vitamin D naturally when your skin is exposed to sunlight, but indoor living and long winters commonly mean that it’s likely that you aren't making enough of this vitamin on your own.
For this reason, vitamin D3 - the active form of vitamin D that's easy for your body to use - is a commonly recommended dietary supplement.
But what is the optimal daily dosage of vitamin D3? And is there anything else you should know about vitamin D3 benefits and dosing? Let's explore.
What Is Vitamin D?
Vitamin D is what is typically known as a fat-soluble vitamin with several possibly important roles in the body. Here are the most common benefits of vitamin D3.1
First and foremost, it may promote calcium absorption so that your body doesn't need to borrow calcium from your bones. For this reason alone, it may be extremely important for bone health.
Vitamin D is also thought to support immune function as well as help reduce inflammation. In many inflammatory or autoimmune conditions, researchers have found that vitamin D deficiency plays a role in the process.
Vitamin D also plays a primary role in cell growth, often making it extremely important for people of all ages to get enough of.
There are two primary supplementary types of this vitamin: vitamin D2 and vitamin D3. Vitamin D2 still needs to be activated in the body for it to be used appropriately, which adds yet another step in the process, so vitamin D3 is typically the preferred supplemental form to use for its ability to raise and maintain blood vitamin D levels most efficiently.
Recommended Daily Intake of Vitamin D3
The Recommended Dietary Allowance (RDA) for vitamin D is:
- 400 IU (10 mcg) daily for infants (less than one year)
- 600 IU (15 mcg) daily for people aged 1-70
- 800 IU (20 mcg) daily for people over 70
However, many health experts consider these recommendations to be too low. Some research suggests that all people require at least 3,000-7,000 IU per day as the recommended daily dose of vitamin D3. In cases of vitamin D deficiency, taking higher doses may be necessary to restore optimal blood levels.2
Factors Influencing Vitamin D3 Requirements
Several factors may influence how much vitamin D3 you need to supplement with, including:3
- Location: Where you live and how much sun exposure the region gets can drastically affect how much vitamin D3 you should take daily. People who live in tropical areas that are closer to the equator generally have milder winters and more sunlight, so they may need less supplementation (although if these people aren't outside often or are too covered, they may still need to supplement). People who live in northern latitudes usually don't receive enough UVB radiation to synthesize vitamin D during cold, dark winters - so supplementation can be a valuable tool for optimal health.
- Skin pigmentation: If your skin is darker, it is thought that you will produce less vitamin D from sun exposure than people who are lighter skinned. If this is you, you may need to spend more time outside than others in order to synthesize enough vitamin D.
- Age: Aging can affect our bodies' ability to create vitamin D from sunlight. Elderly people may produce less vitamin D from the same amount of sun exposure than younger people, which is why the RDA for people over 70 years old is higher than the rest of the adult population.
- Body weight: Vitamin D is typically fat-soluble and may become "trapped" in the fat cells of people with a higher body fat composition. People in bigger bodies may need more vitamin D to compensate for this effect.
- Digestive health: Finally, any disease that limits the body's ability to absorb nutrients, such as Crohn's disease or celiac disease, should reduce how much vitamin D is absorbed from supplements. This can effectively increase a person's vitamin D requirements from supplements.
Why It's Important to Combine D3 with K2
Vitamin D works synergistically with another vitamin that we don't typically get enough of - vitamin K2. These two vitamins often work together to direct calcium absorption and usage to protect your bones and soft tissues.4,5 Here's how they work:
First, vitamin D3 helps the body absorb more calcium from food and transport it throughout the body.
Then, vitamin K2 most likely directs the calcium - telling it where to go. It commonly leads calcium to the bones and teeth, and away from soft tissues, such as blood vessels. This activity is essential for preventing calcium deposits from forming in the soft tissues, which can drastically increase heart disease risk.
For this reason, high dose vitamin D3 without also supplementing with vitamin K2 may not be advisable. Vitamin D3/K2 can result in better heart and bone health than taking vitamin D3 alone.
Risks of Vitamin D3 Deficiency
Deficiency is common. Vitamin D3 deficiency symptoms may include:1
- Fatigue
- Bone pain
- Muscle pain
- Hair loss
- Osteoporosis
- Slow healing
- Depression
Vitamin D deficiency has also been linked to several disease states, including heart disease, diabetes, depression, autoimmune conditions, and more.
Safe Upper Limits for Vitamin D3 Intake
Vitamin D3 toxicity is rare, but because it's fat-soluble it may build up in the fat cells over time and cause issues such as nausea, vomiting, and kidney problems. The Tolerable Upper Intake Level (UL) is currently 4,000 IU per day, though many physicians recommend that their patients take much higher doses to replenish low vitamin D stores.1
Speak to Your Doctor Before Adding a Vitamin D Supplement to Your Daily Routine
While many people may greatly benefit from taking 5,000 IU of supplementary vitamin D per day, it is possible to take too much vitamin D3. It's extremely important to speak with your doctor before adding a vitamin D supplement to your routine.
To guide vitamin D dosing decisions, it's a good idea to have your blood levels checked first. You will also want to choose the vitamin D dose that will help you effectively replenish your vitamin D stores, so it's important to consult your doctor before adding this supplement to your routine.
Best Vitamin D Supplement
At this point, you may be wondering - what's the best vitamin D3 supplement for me?
Here are a few things to look for:
- It should contain vitamin D in its active form, vitamin D3.
- It typically pairs vitamin D3 and vitamin K2 for optimal bone and heart health.
- It should contain enough vitamin D3 that it can help replenish blood levels for anyone, regardless of their age, sun exposure, weight, or lifestyle.
That's why we commonly recommend Body Kitchen's Vitamin D + K2, as one of the best vitamin D3 and K2 supplements available. One small capsule contains a powerful 5,000 IU of vitamin D along with 180 micrograms of vitamin K2.
Vitamin D supplements are not always beneficial. They're also thought of as one part of a larger wellness puzzle that also includes a healthy diet, regular exercise, good sleep, and stress reduction.