Vitamin D is an essential nutrient, and as you get older, you need a lot more of it. The recommended daily intake of vitamin D goes up 33% after you turn 70.

The primary source of vitamin D is sunlight. But increasing your exposure to the sun’s rays also comes with a significant downside, especially as you age: skin damage. Older adults are at higher risk than younger adults of developing melanoma – a potentially fatal form of skin cancer caused by ultraviolet-b (UV-B) radiation from the sun.

You don’t have to rely on only the sun for your vitamin D. There are other sources as well, and you can work with your health care provider to ensure you’re getting enough.

Why is vitamin D so important?

Let’s talk about how vitamin D supports your health:

• Bone health. Without enough vitamin D, your body can’t absorb enough calcium to keep your bones healthy and strong.
• Cognitive health. Research shows that a lack of vitamin D can contribute to difficulty in thinking and learning – also known as cognitive decline.
• Other conditions. Research is under way, though not conclusive, on vitamin D’s role in reducing the risk of conditions such as cancer or multiple sclerosis.

How much vitamin D do I need?

The amount of vitamin D you need is measured in international units (IU).

The older you get, the more vitamin D you need. Recommended daily amounts by age:

• Birth-12 months: 400 IU
• 1-70 years: 600 IU
• 70 years and older: 800 IU

How does sunlight give you vitamin D?

During exposure to sunlight, the skin absorbs UV-B radiation, which your body turns into vitamin D. The amount of vitamin D you get from sunlight depends on:

• Sun exposure. Bare skin absorbs UV-B rays, so the more skin exposed, the more vitamin D you produce. Also, glass or any material used for windows blocks UV-B rays, so indoors sun exposure doesn’t produce vitamin D.
• Skin tone. The darker your skin, the more exposure you’ll need to convert UV-B rays to vitamin D.
• Sunscreen use. Sunscreen blocks UV-B rays, although studies show most people don’t use enough of it to markedly reduce UV-B rays.
• In the United States, the farther north of the equator you are, the fewer UV-B rays reach Earth’s surface, and you, during the winter.
• Air pollution. Smoke, smog or anything that reduces air quality also reduces UV-B ray penetration.
• Many studies show that the older you get, the less your body is able to convert UV-B rays to vitamin D.

It probably takes less time in the sun than you realize to get a sufficient amount of vitamin D. The NIH notes that 5–30 minutes of sun exposure to face, arms, or legs twice a week may suffice, depending on skin tone, location, and season.

However, you should take precautions to protect yourself from sun damage. Prolonged exposure to the sun is a risk factor in melanoma and other skin cancers. And while the sun is the primary way to get vitamin D, there are other ways to absorb it.

What are other ways of getting vitamin D?

Sunlight is considered the primary way of getting vitamin D because few foods have it naturally. The U.S. government’s dietary guidelines show the only foods that satisfy daily vitamin D recommendations in their standard serving size, are lean or low-fat salmon, and freshwater rainbow trout.

Other fish such as canned tuna, herring, sardines, tilapia and flounder also are sources of vitamin D.

However, since the 1940s and 1950s, foods such as bread, cereals, milk and milk substitutes, yogurt, cheese and orange juice are fortified with vitamin D to help people incorporate it into their diets. Fortification is the process of adding vitamins and minerals to food as it is being produced. Also, some kinds of mushrooms that naturally have vitamin D are exposed to extra UV-B light to increase their levels.

Vitamin D supplements are also widely available. Let your doctor or advanced practice clinician (APC) know if you’re taking them, or plan to take them. That way, they can check if your supplement is worthwhile and make sure it doesn’t interact with any other medications you’re taking.

Should I talk to my doctor about my vitamin D level?

While research is ongoing on the effects of low vitamin D on various diseases and conditions, we know low vitamin D can affect your bone strength, putting you at greater risk for osteoporosis or broken bones.

The best way to know whether you’re getting enough vitamin D is to get a blood test from your health provider. Your doctor or APC can look at your vitamin D level, along with other information about your health. Then, you can work together on a strategy to get your vitamin D level where it needs to be, in the best and safest way possible.

References

1. Mayo Clinic. “Vitamin D.” Accessed May 27, 2025. https://www.mayoclinic.org/drugs-supplements-vitamin-d/art-20363792
2. National Institutes of Health. “Vitamin D: Fact Sheet for Professionals.” Accessed May 27, 2025. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
3. “Vitamin D in the older population: a consensus statement.” Accessed May 28, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC9607753/
4. JSTOR Daily. “How Does the Body Make Vitamin D from Sunlight?” Accessed May 28, 2025. https://daily.jstor.org/how-does-the-body-make-vitamin-d-from-sunlight/
5. Oregon State University, Linus Pauling Institute, Micronutrient Information Center. “Vitamin D and Skin Health.” https://lpi.oregonstate.edu/mic/health-disease/skin-health/vitamin-D