The easiest nutrition change you can make: take vitamin D

I usually hesitate to highlight the benefits of just one vitamin, because I think it’s more useful to know how to get many key nutrients from a variety of foods.

But Vitamin D is a standout. Vitamin D is important, really important. I cannot emphasize this enough. Luckily, it’s often easy to correct a deficiency. But eating Vitamin D-rich foods is not the only answer. In fact, food is not enough.

With the holidays in full swing, respiratory viruses circulating and ski days upon us, it’s the perfect time to talk about vitamin D.

What’s the big deal with Vitamin D?

• Vitamin D is essential for bone health, immune function and mood. Deficiency has also been associated with certain cancers, autoimmune conditions, muscle weakness and pain, and the incidence and severity of the big “C” respiratory infection. It is anti-inflammatory and has other protective effects.* 

• Vitamin D is a hormone that your body makes from sunlight ☀️. Unless you eat several servings of trout or salmon daily, you won’t get enough from food and likely need a supplement.

• How much vitamin D your body makes from sun exposure depends on the time of year, geography (angle of sun, cloud cover, latitude), your age, skin color and other factors.

I ask all my clients about their vitamin D level. Only a few have had optimal values without taking a vitamin D supplement. I first saw this when I met with a couple, both of whom had healthy D levels. I was shocked! Come to find out they regularly travel to Mexico. Near the equator, their bodies are making vitamin D quite well.

How much vitamin D do I need?

Deficiency can occur for many reasons, which include an indoor lifestyle, living where sunlight is limited, and eating a diet low in D-containing foods such as fatty fish, egg yolks, cod liver oil and fortified milk and orange juice. As well, people with darker skin don’t convert sunlight into active vitamin D as efficiently as those with lighter skin. Conversion also slows as we age. (Less commonly, a genetic variation can also make the conversion of sunlight to vitamin D more difficult.)

Rickets, the softening and weakening of bones that can occur in children with a prolonged and severe deficiency of vitamin D, calcium or phosphorus, may seem like a thing of the past, but it still afflicts children around the world. (Vitamin D is required to absorb calcium and phosphorus.)

Signs that you may be low include feeling sad or depressed, having difficulty sleeping, muscle aches and pale skin.

How much vitamin D you need depends on your current level, as measured on a blood test, and the optimal level is a subject of great debate.  

Vitamin D results on a lab test are considered “normal” from 30 to 100 ng/mL. That’s a huge range! Below 20 ng/mL is considered deficient.

Much of the research on vitamin D, as it relates to various specific health outcomes, suggests an optimal level is the 40-60 ng/mL range. (However, there are certain health considerations in which a higher or lower level may be appropriate). I can help you supplement the right amount and work in partnership with your doctor to get you to the right level.

The recommended daily amount (RDA) of vitamin D is 400 international units (IU) for children under 1 year, 600 IU for people ages 1 to 70 years, and 800 IU for people age 70 and older.

However, these amounts are often not enough to achieve an optimal D level.

When you supplement vitamin D, it’s important to recheck your level annually, as absorption is cumulative and Vitamin D excess, while less common than deficiency, can be dangerous. A few risks are soft-tissue calcification and hypercalcemia (too much calcium in the blood).     

What to do next

1.  Test your vitamin D. Many primary care doctors do this with routine bloodwork. You also can order your own vitamin D test for about $100.

2.  Supplement based on your results. I can help. I start many clients at a higher dose during winter months (when levels naturally decline) or to correct a deficiency, then reduce them to a maintenance dose after 6 months. Depending on your individual health factors, I may recommend vitamin D3 with vitamin K2, as they work synergistically. Buy a quality brand — see my article on supplements.

Vitamin D3 (along with vitamins A, E and K) is fat-soluble and is best absorbed with fat-containing foods.

Should I get more sun exposure?

That depends. We know that sunscreen helps to protect from skin cancer, but it also impedes this valuable vitamin D-making process.  

Talk to your primary care doctor and dermatologist as it relates to benefits vs. risks for you. Factors they may consider: your history of sun exposure and skin cancers, skin color and ancestry.

For me, ancestry is almost entirely from the British Isles, so you know, really white. That ups my risk. (Side note: People of color produce more melanin, the skin pigment that makes skin darker. This helps protect against skin cancer, but also reduces vitamin D synthesis from the sun).

As for my history, I fried my face skiing on a slightly overcast day in 8th grade, and turned into a bubbly, painful mess for days. The dermatologist my mom took me to said, “If you ever do this again you will get skin cancer.” Scare tactic or fact? Who knows? I didn’t like the guy, but he did scare me into a sun-safe plan.

Here’s how I thread the needle on sun exposure: Year-round, I wear a zinc-based** 30 SPF sunscreen on my face, neck and hands, areas exposed much more than other parts of the body. (I use 50 SPF if I’m so lucky to be at the beach … or skiing). In the summer, I wear a wide-brimmed hat outside.

In the months when sun exposure helps my body make vitamin D, roughly April to October in Colorado, I let my legs and arms get sun for about 20 minutes, several days a week, before I apply sunscreen.

As for the skin cancer? So far so good! I see my dermatologist regularly and I hope you do, too.

*IMPORTANT NOTE: The information in this article does not constitute medical advice. Please talk with a health professional about taking vitamin supplements. Research references are available upon request.

**I like zinc-based sunscreen because it works! Plus many sunscreens on the market contain chemicals that post other health risks.