Vitamin D, known as the sunshine vitamin, might be more crucial to your health than you think. According to a new, comprehensive review of clinical studies, a median daily intake of 3,320 IU (or 83 micrograms) of vitamin D is linked to improved cardiovascular health, including reductions in blood pressure, total cholesterol, hemoglobin A1C, and fasting blood insulin and glucose.

The meta-analysis covered 99 randomized, controlled trials from all over the globe and evaluated the benefits of vitamin D supplements. The studies evaluated data from 17,656 participants overall. Their baselines of serum vitamin D ranged from severely deficient (5.59 ng/mL) to sufficient (35.01 ng/mL). However, even "sufficient" can equate to low vitamin D levels. For context, optimal levels range between 50 to 80 ng/mL.

The analysis highlights not only the benefits of vitamin D but also the need for personalized intervention strategies that account for individual characteristics, like age and BMI. For example, heavier/obese individuals will likely need a higher dose of vitamin D to achieve optimal levels.

The impact of vitamin D on health

The doses of vitamin D administered to participants ranged from 40 IU to 7,000 IU per day for a minimum of six weeks to a maximum of seven years. The meta-analysis found two groups of people experienced the greatest benefits from an increased intake:

• People with a BMI under 30
• Individuals aged 50 or older

Here are some of the more prominent findings from the meta-analysis:

• It significantly reduced both systolic and diastolic blood pressure.
• Vitamin D supplementation significantly decreased total cholesterol levels. This was more pronounced with higher doses for at least three months.
• It significantly reduced biomarkers of blood sugar status, like fasting blood glucose, hemoglobin A1C and fasting blood insulin.

Note: When it comes to this essential vitamin, different people will have different needs. Regular lab work can help individuals understand how they might need to adjust their dosage over time.

How does vitamin D benefit me?

Vitamin D, 25-Hydroxy Blood Test

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Vitamin D can support the immune system (making it especially helpful in the wintertime), heart health and blood pressure, kidney health, brain functioning and cognition, and bone health since a vitamin D deficiency can cause rickets, a bone disease that leads to weak and soft bones in children, as well as osteoporosis and osteomalacia.

Correcting a vitamin D deficiency can also result in weight loss and reduced inflammation! In other words, vitamin D is a whole-body (and whole-mind) health superstar!

What are the best dietary sources of vitamin D?

Generally, we get most of our vitamin D from sun exposure, not from our diets. In fact, it's quite difficult to get enough vitamin D from food alone.

However, if you're trying to boost your levels, consider incorporating the following foods into your nutrition:

1. Cod liver oil

2. Fatty fish, like mackerel, salmon, trout, sardines and tuna (also great sources of protein!)

3. Mushrooms, which typically contain vitamin D2, specifically

4. Certain cheeses, like Fontina and Muenster

5. Beef liver

6. Dark chocolate, which is also an excellent source of antioxidants and magnesium

7. Eggs, especially the yolks—hello, healthy fats!

You can also eat more foods fortified with vitamin D, like milk, yogurt, orange juice, plant-based beverages, and some cereals. Pro tip: Be mindful of consuming highly processed foods.

Ultimately, getting more sun exposure can help you combat vitamin D deficiency. That's because the sun triggers a chemical response in your body that allows you to produce your own vitamin D. If you're spending a lot of time indoors (for instance, if you have an office job or it's the middle of winter), this could explain your vitamin D deficiency.

The good news is that you don't need to spend much time outside to make a difference—in fact, if you notice a tan, you've been outside too long. Going for a quick walk in the morning or simply standing out in your backyard for a few minutes with your morning cup of joe is the perfect approach!

But don't neglect your sunscreen! While it may inhibit the effect of the sun on your body's vitamin D production, it's also important to protect your skin from too much UV exposure. Wear a thin layer on your face and neck, and limit sun exposure during midday when the sun's rays are the most powerful.

How can I test my vitamin D levels to ensure I’m getting enough?

You can test your serum levels regularly with a vitamin D blood test—every few months should be adequate to track your progress. Start by monitoring your levels over different seasons, your nutrition, the supplements and/or medication you're taking (some medications can cause a deficiency), and so on, with your healthcare provider. Then, you can tweak your dosage as needed to get enough vitamin D.

For example, you might need a higher intake in the winter months when you're inside and curled under a blanket, compared to the warmer spring and summer months when you spend more time outside.

Whether you want to improve your bone health and protect yourself against osteoporosis, support your immune system to fend off that pesky yearly cold, or keep your brain sharp so you can crush it at work or school, improving your vitamin D intake can help.

In addition to a healthy diet, stress management, plenty of sleep, hydration, and daily movement, taking vitamin D can vastly improve your health from head to toe.

Pro tip: Learn more about how to raise your vitamin D levels quickly.

References

• An P, et al. "Modifiers of the Effects of Vitamin D Supplementation on Cardiometabolic Risk Factors: A Systemic Review and Meta-Analysis." Engineering. November 2024. https://www.sciencedirect.com/science/article/pii/S2095809924003990?via%3Dihub
• Benedik E. "Sources of Vitamin D for Humans." Int J Vitam Nutr Res. March 2022. https://pubmed.ncbi.nlm.nih.gov/34658250/
• Santa K, et al. "The Potential Use of Vitamin D3 and Phytochemicals for Their Anti-Aging Effects." Int J Mol Sci. February 2024. https://pubmed.ncbi.nlm.nih.gov/38396804/

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The Life Extension Health News team delivers accurate information about vitamins, nutrition and aging. Our stories rely on multiple, authoritative sources and experts. We keep our content accurate and trustworthy, by submitting it to a medical reviewer.