Your Vitamin D Cheat Sheet February 21, 2017 09:44

Not sure where to start when it comes to vitamin D? Here's a good place.

Vitamin D

Vitamin D gets a lot of press for helping to build strong bones, but this hormone (yep, vitamin D is actually a hormone), is more than just a one-trick pony and has benefits all over your body. But before you start downing pills for every ailment, check out our vitamin D cheat sheet for the fast facts on what you need to know about improving your health:

How Much Do I Need?
"The Institute of Medicine helps establish the U.S. guidelines for vitamin D, and now they say based on age and gender, 600 to 800 IU [international units] is good enough for daily intake," says Mark Moyad, MD, MPH, author of The Supplement Handbook. (However his personal opinion is that it should be closer to 800 to 1000 IU, since this would raise the blood test 10 points over a year.)

Is a Blood Test Worth It?
Short answer: Probably not. "The blood tests have not been validated or completely reliable, and they can be really expensive," says Dr. Moyad. He says that, if your insurance isn't going to cover it, it's only worth your money if you think you could have a deficiency that is making a big impact on your health (like being very prone to infection, having weak bones, or suffering multiple falls).

Vitamin D

"The test becomes valuable when you pick up someone that has a number in the single digits," he says. He considers 30 to 40 ng/mL to be normal, but he explains that there isn't one agreed-upon standard for normal. "We all agree less than 10 ng/ML, or "deficiency," is bad, but others say less than 20, or insufficiency, is also concerning."

So How Could Vitamin D Be Affecting My Health?

Low vitamin D has been implicated in...
Parkinson's
Dr. Moyad is pretty conservative when it comes to recommending vitamin D supplements, but he wholeheartedly gives it a thumbs up for Parkinson's disease patients. "Vitamin D reduces the risk of falls in older people, and PD patients have a highter risk of falls and hip fractures (plus, they tend to be low in D)," he explains. He also points out that there is research that shows that vitamin D supplementation may be able to slow or stop the progression of this disease.

Dementia
Omega-3's get a lot of attention for giving your brain a tune-up, but getting enough vitamin D may also help you keep your mind sharp as you age. Research has found that those low levels of vitamin D increased the risk for dementia by 53 percent and severe deficiencies increased the risk by 125 percent.

Vitamin D

"The test becomes valuable when you pick up someone that has a number in the single digits," he says. He considers 30 to 40 ng/mL to be normal, but he explains that there isn't one agreed-upon standard for normal. "We all agree less than 10 ng/ML, or "deficiency," is bad, but others say less than 20, or insufficiency, is also concerning."

 

Depression
Seasonal Affective Disorder, or SAD, is more than just feeling a little low during the winter. It is characterized by real depressive symptoms and extreme lethargy. This condition is linked to the lack of sun light in wintertime, and now, research published in Medical Hypotheses have also discovered that SAD is also related to vitamin D deficiency.

This finding may just be a correlation: The lack of sunlight causes both SAD and low vitamin D levels, since sun exposure encourages the body to produce more vitamin D. However, the researchers point out that vitamin D is involved in the process of making the body's "happiness" hormones, serotonin and dopamine. Furthermore, previous studies have found that low vitamin D is linked to non-seasonal depression.

Asthma and Lung Disease
Correlational studies have found that children with low vitamin D levels were also more likely to have severe asthma, and new research is showing that this link may extend into other lung issues. Research published in The Lancet Respiratory Medicine  found that taking vitamin D supplements reduced flare-ups of chronic obstructive pulmonary disease (aka COPD), including chronic bronchitis and emphysema, by 40 percent versus a placebo.

Type 1 Diabetes
Didn't get enough vitamin D as a kid? That may explain your risk for type 1 diabetes. "Children who currently have normal D levels and whose mothers had normal D levels when pregnant with them appear to have a lower risk of getting type 1 diabetes," says Dr. Moyad. "Vitamin D plays a role in immune surveillance and improving immune function, and since type 1 diabetes is really an autoimmune disease, D may have a role in preventing the body from attacking the cells of the pancreas that produce and secrete insulin."

Vitamin D

Is There Anything Vitamin D Can't Fix?
Yes. While there are a lot of benefits to vitamin D, it's not a cure-all. Dr. Moyad says that vitamin D doesn't have benefits for macular degeneration, cataracts, hair loss, high cholesterol, or hypertension. Any link between these issues and vitamin D is mediated by weight: Body fat gobbles up vitamin D from the blood, perhaps making you deficient, but it's not the deficiency that causes the problem—it's the excess body weight.

How Can I Be Sure That I'm Getting Enough Vitamin D?
The best way to have a healthy level of vitamin D is through your food. Dr. Moyad recommends eating foods naturally rich in vitamin D, such as fatty fish, mushrooms, and eggs, or foods fortified with vitamin D, such as almond or flaxseed milk.