5 Things You Need To Know about Vitamin D

Judy Gerstel | September 23rd, 2015

There’s been a lot of buzz around Vitamin D and for good reason.

“D” deficiency has been linked to a number of health risks including cognitive decline and dementia. It also helps to keep skin bones strong, boosts immunity, fends off depression, supports heart health and lowers cancer risk.

Here, 5 things you need to know about this essential nutrient.

1. Vitamin D is not actually a vitamin. So what is it?

It’s a hormone produced by your body when your skin is exposed to sunlight, specifically, the UVB rays. Very little sun exposure is needed to provide your body’s needs.

Even if you live in an area where you get little strong sun in winter, advises Dr. Andrew Weil, adequate exposure during the rest of the year will allow your body to stockpile enough “D” to last you through the winter months.

2. Will sunscreen block Vitamin D production?

Isn’t it risky to spend time in the sun without sunscreen? Maybe and yes. The same UVB rays that produce vitamin D also cause skin cancer.

So there’s a trade-off between increasing risk of vitamin D deficiency and increasing risk of aged skin and skin cancer. Several previous studies that have since come into question for their methods have shown that sunscreen blocks vitamin D production. However, a respected 2014 study by King’s College London’s Institute of Dermatology showed that our bodies can produce vitamin D even while wearing sunscreen.

Researchers measured the vitamin D levels of 79 men and women before and after a one-week beach trip to a Spanish island. Half of the participants made sure to properly apply a sunscreen with SPF 15, while the other half hit the beach with bare skin. Both groups’ vitamin D levels soared.

While the bare-skinned group had slightly higher levels of vitamin D at the end of the study, the difference between the groups wasn’t significant enough to warrant skipping sunscreen.

It’s still not known whether a higher SPF could interrupt vitamin D production or exactly how much sun you need for to produce sufficient vitamin D synthesis.

3. How else can you get vitamin D?

Vitamin D supplements are considered safe when when taken by mouth in doses of 4,000 IU of vitamin D3 daily. Studies earlier this year are pointing to raising the recommended amount to as much as 7,000 IU total from all sources.(There are two versions of “D”: Vitamin D2, known as ergocalciferol, and vitamin D3, also known as cholecalciferol, which is thought to be the more potent and favourable.

Giving kids cod liver oil used to be a common way to make sure they had sufficient “D” and it still works, as do other fish oils. But the tastiest way to get a healthy dose is to dine on wild salmon. It’s at the top of the list of foods that provide the most vitamin D .

All the fatty fishes — herring, sardines, mackerel, tuna — as well as oysters provide high amounts of vitamin D. Other foods high in “D” include mushrooms, beef liver, cheese, and egg yolks. Also, it’s added to many foods such as milk, soy milk, orange juice and some cereals.

4. Why is Vitamin D so important?

Besides the new findings about the “D” deficiency link to cognitive decline and dementia, the vitamin is an essential nutrient keeps bones strong, boosts immunity, fends off depression, supports heart health and lowers cancer risk, according to data from the U.S. National Institutes of Health. It also keeps skin and hair healthy. A severe deficiency causes rickets.

5. How do you know if you have sufficient vitamin D levels?

The most accurate way to measure how much vitamin D is in your body is the 25-hydroxy vitamin D blood test. A level of 20 nanograms/milliliter to 50 ng/mL is considered adequate for healthy people. A level less than 12 ng/mL indicates vitamin D deficiency.

With this new finding about the link between “D” deficiency and cognitive decline, older people would be wise to make sure their “D” levels are tested when their doctors order blood tests for annual check-ups.