We all know that sunshine, AKA the most obvious way to get vitamin D, is good for you. Not too much (wear sunscreen!), but just enough to keep you healthy and happy.
But the truth is that vitamin D, like many other nutrients, can be dangerous if you have too much of it in your system.
So, before you blast yourself with one of those seasonal depression lamps while popping 10,000 IU in vitamin D supplements a day, have a think about how much vitamin D you really need — and the best way to get it.
The Sunshine Vitamin Isn’t Actually a Vitamin
Raise your hand If you knew that vitamin D isn’t actually a vitamin. Mind-blowing, right?
Vitamin D is a prohormone. This means that when your body receives it, it stimulates the production of a hormone, usually referred to as “activated vitamin D” or calcitriol.
Your body needs vitamin D to help it absorb calcium and phosphorus, two key building blocks for your bones. Plus, it does wonders for your immune system.
If you’re curious about all the incredible benefits of vitamin D, we’ve rounded a few of them up for you.
But is there such thing as too much of a good thing?
What is Vitamin D Toxicity?
Toxicity refers to the degree of which a substance, or mix of substances, can do harm to your body. When this threshold is crossed, it can mean that your body will start to experience negative side effects.
Vitamin D toxicity simply refers to having too much in your system. Unpleasant — even dangerous — things can start to happen at this point.
Your body isn’t going to overdose on vitamin D from sunshine. Supplements that are the culprit, so it’s important to take care when incorporating them into your diet.
What Are the Symptoms of Vitamin D Toxicity?
If you feel like you might be experiencing hypervitaminosis D (the fancy medical term for vitamin D toxicity), keep these symptoms top of mind:
- Vomiting and nausea
- Fatigue and weakness
- Lack of appetite
In particular, too much vitamin D can cause a build-up of calcium in your blood (hypercalcemia), which in turn can cause calcification. Watch for hardened areas forming in your soft tissue, as this is a tell-tale sign of toxicity.
So How Much Vitamin D is Too Much?
According to the Mayo Clinic, 60,000 IUs a day (taken over several months) is enough to cause toxicity. 1
Recommended Daily Dosage
How much vitamin D you need can depend on a number of factors. Your age, weight, and racial makeup can all play a role in determining how much of it your body requires.
For example, if your ancestors lived in northern, arctic regions with less sunlight, you might not need much. On the other hand, if you hail from somewhere near the equator, chances are your dosage will need to be higher.2
Plus, environmental factors such as latitude, season, and sun exposure are also part of the mix.
Studies have also suggested that obese individuals should increase their supplementation by two or three times the amount recommended for their age group.3
Everyone is different, but below are some dosage guidelines from the Institute of Medicine:
- Infants age 0 to 6 months: adequate intake, 400 IU/day; maximum safe upper level of intake, 1,000 IU/day
- Infants age 6 to 12 months: adequate intake, 400 IU/day; maximum safe upper level of intake, 1,500 IU/day
- Age 1-3 years: adequate intake, 600 IU/day; maximum safe upper level of intake, 2,500 IU/day
- Age 4-8 years: adequate intake, 600 IU/day; maximum safe upper level of intake, 3,000 IU/day
- Age 9-70: adequate intake, 600 IU/day; maximum safe upper level of intake, 4,000 IU/day
- Age 71+ years: adequate intake, 800 IU/day; maximum safe upper level of intake, 4,000 IU/day
So the short answer is: Discuss with your doctor what might be the right dosage for you (and always follow the label).
If you're already on the D train - check out our blog on when to take vitamin D.
Am I Getting Enough Vitamin D?
It seems like every time we hear about vitamin D, it’s because we’re not getting enough of it. And in fact, it’s true. Over 40% of Americans don’t get enough vitamin D; our lifestyles aren’t what they used to be, and we spend a lot more time indoors.
Worse still, it’s difficult to find foods that are naturally rich in vitamin D. So, it’s safe to say that unless we make an effort to get outside and soak up the sun, our chances of getting enough are slim.
Which brings up another notion: When most of us think about getting more, we turn to sunlight. But there must be another way, no?
There is: supplements! Vitamin D supplements are a great way to get your “sunshine” from the inside-out.
If you’re already taking one, be sure to check out our post on when to take vitamin D for maximum efficiency and catching maximum sleep.
So our recommendation? Take your vitamin D during the day with a big, nutritious meal, and get that inner sunshine shining.