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Even if you live in sunny California, chances are pretty good that you’ll still benefit from a boost of vitamin D. About 42% of Americans are deficient in vitamin D, and people over 65 are more likely to have a deficiency.
We spoke with Dr. KC Hayes, Professor Emeritus at Brandies University and nutrition expert, to answer our most pressing questions about who needs to take a vitamin D supplement, what to look for in a supplement, and how much vitamin D you should be taking.
What does vitamin D do?
Vitamin D plays a few essential roles in the body. Your bones need calcium and phosphorus to stay strong and resist diseases like osteoporosis, breaks, and fractures. Vitamin D allows your body absorb to calcium.
It also supports muscle and nerve development and plays a role in a strong immune system. Some studies suggest that vitamin D supplementation can prevent the flu and other respiratory infections.
Vitamin D testing
To know for sure whether you’re deficient, you can ask your doctor for a vitamin D test, which requires a blood sample. Hayes points out that “When you receive your vitamin D test results, it’s important to know which unit of measurement, ng/mL or nmol/L you’re dealing with. In the US, the most common test measures nanograms per milliliter, or ng/mL.”
Doctors still debate what qualifies as a healthy level of vitamin D. However, accoring to Hayes, “Most experts agree that a blood level below 25 nmol/L is considered deficient. Levels this low are associated with bone diseases like rickets or osteomalacia.”
“Some experts argue that 25-30 nmol/L in the blood is sufficient, some say a level over 50 nmol/L is optimal for good bone health for most people, while others again advocate for 75 nmol/L or even higher,” says Hayes.
Can you have too much vitamin D?
Yes, it is possible to reach blood levels of vitamin D that exceed the healthy range. This can lead to conditions such as hypercalcemia and tissue damage.
Hayes notes that “Excess or toxic levels of vitamin D are thought be over 250 nmol/L, but there are differing views on this. Vitamin D concentration can be very high before hypercalcemia occurs. Several studies suggest it is safe to have a vitamin D concentration of 300 nmol/L.”
And like most health metrics, there’s no one-size-fits-all recommendation. “Each person’s optimal vitamin D levels are influenced by age, gender, weight, and overall health,” says Hayes.
How much vitamin D should I take?
If your blood levels are looking low, you live in a place without regular sunshine, or you don’t spend as much time outside as you’d like, a supplement is a good idea. Plus, it’s not expensive. Dr. Hayes follows a dosing schedule created by Dr. John Cannell of the Vitamin D Council.
He takes 1000IU of Vitamin D during the summer months, and increases to 2000IU per day from September to April, when the sun is weaker. If you have a low baseline vitamin D level, you may want to start with a higher dose, such as 5000IU per day.
It’s important to note that “Vitamin D (as well as vitamin A) can be toxic at high doses (greater than 50,000ID per day) for prolonged periods of time,” but if you’d rather stick to the same dose year-round, Hayes recommends taking 2000IU per day.
What vitamin D supplement is best?
You can find vitamin D in a wide range of doses and forms, from soft gels to pills to liquid droppers.
To maximize the efficacy of your supplement, you may want to choose one that contains both vitamin D and vitamin K2. Studies suggest that taking both nutrients at the same time can be better for your joint and bone health than taking them separately. NutraChamps Vitamin K2 + D dropper is a great liquid supplement that packs 5000IU of vitamin D and 200 mcg of vitamin K2.
Vitamin D3 K2 Drops | Vegan Liquid Vitamin D3 5000 IU & K2 with MK7 & MK4
$19.95
If you prefer a softgel, Naturewise makes 5000 IU supplements that are third-party lab tested for potency and efficacy. A great tablet option is Bronson’s organic 2000 IU supplement.
NatureWise Vitamin D3 5000iu (125 mcg) 1 Year Supply
$14.99
Or, if you prefer to chew your vitamins (or you’re working on upping kids’ D levels), Nordic Naturals makes tasty 1000IU gummies that are also fortified with K2.
Nordic Naturals Vitamin D3 + K2 Gummies, Pomegranate
Nordic Naturals
amazon.com
$21.21
However you take your supplement, adding vitamin D to your daily routine can make a major impact on your long-term health.