Health Hotline Magazine | April 2025

Looking for an easy way to support heart health? Studies show that increasing vitamin D levels through supplementation can reduce the risk of cardiovascular disease (CVD) and stroke by decreasing blood pressure, protecting against arterial stiffness and arterial wall thickening, improving endothelial function, and supporting blood sugar homeostasis, all critical markers of cardiovascular health. A meta-analysis of 34 studies, which included 80,667 participants, found that for every 10 ng/mL increase in serum vitamin D, there was a 10 percent lower risk of cardiovascular events like stroke and heart attack and a 12 percent lower risk of cardiovascular mortality.

Vitamin D plays an important role in brain development and func tion. It is necessary for neuronal development, including those neurons involved in learning and memory, and it’s been shown to help kids with attention deficit hyperactivity disorder (ADHD). Studies show that when children with ADHD and vitamin D defi ciency were supplemented with 3,000 IU of vitamin D daily for 12 weeks (in addition to receiving standard therapy for ADHD) they saw significant improvements in both inattention and hyperactivi ty compared to a placebo. Low levels of vitamin D present a real risk for cognitive decline as we age. A 2017 review and meta-analysis showed that vitamin D deficiency (levels less than 10 ng/mL) increases the risk for de mentia, especially in adults 65 and older. Optimal levels of vitamin D also provide possible protection against the neurodegenerative processes associated with Alzheimer’s disease, including the clear ance of amyloid-ß plaques, a hallmark of Alzheimer’s. Another reason to incorporate vitamin D into your daily routine is its mood-boosting and stress-mitigating benefits. A 2021 study investigated the impact of vitamin D deficiency on mental health in university students with eye-opening results. Of the 480 stu dents recruited for the study, 287 (nearly 60 percent) had a vi tamin D deficiency. The prevalence of depression, anxiety, and stress among the D-deficient students was 60.35%, 6.31%, and 75.08%, respectively. The odds of developing depression, anxiety, and stress were significantly higher in the vitamin D-deficient in dividuals. The research showed a strong association between psy chological stress and vitamin D deficiency, concluding that, “Con trolling vitamin D levels not only helps to control the wide range of psychological burdens but also helps to improve the academic performance of the students.” Vitamin D supplementation has also been shown to positively im pact mood and improve depressive symptoms in children. A 2024 randomized, controlled trial found that supplementing school aged children with 2,000 IU vitamin D daily for nine weeks re sulted in significant reductions in depressive symptoms.

NATURAL VITAMIN D PRODUCTION AND THE FACTORS AT PLAY

Vitamin D is dubbed the “sunshine vitamin” because it’s the only vitamin the human body can produce through exposure to UVB rays; it’s said that we can achieve opti mal vitamin D levels just by spending 20 minutes a day in the sun. But, in reality, many factors come into play for this to hold up. The caveat to optimizing natural vitamin D production is that large areas of the skin (arms, legs, face, and abdomen) need to be exposed to the sun—with out sunscreen (sunscreen with an SPF of 30 reduces the capacity of the skin to produce vitamin D by 95 to 98 per cent). The time of day is also important; between 10 a.m. and 4 p.m. provides the strongest UVB rays that lead to su cient vitamin D synthesis. And as already mentioned, the time of year also matters. Age and skin color are also factors. Younger people tend to have better vitamin D pro duction compared to older adults, and those with lighter skin are more e cient at producing vitamin D compared to people with darker skin. Weight is another factor. Indi viduals with a body mass index (BMI) of 30 or more have been found to generally have lower vitamin D levels and may require more vitamin D to achieve levels of those with normal weight. Other factors that can impact vitamin D production in the body include having adequate magnesium levels, which plays a key role in vitamin D metabolism and absorption, having a healthy liver, which is required to convert vitamin D into its active form, and environmental factors, such as cloud cover, pollution, and altitude, which impact the amount of UVB rays reaching the skin. Lastly, lifestyle factors, such as working indoors during daylight hours, can also impede vitamin D production. UVB radiation does not penetrate glass, so exposure to sunshine indoors or in a car through a window does not produce vitamin D in the body. WHAT ARE OPTIMAL LEVELS? The Endocrine Society, the National and International Osteoporosis Foundation, and the American Geriatric Society define vitamin D deficiency as vitamin D levels in the blood of less than 30 ng/mL. The Endocrine Society recommends a range of 40–60 ng/mL with a daily intake of 400–1,000 International Units (IU) for infants less than one year, 600–1,000 IU for children and adoles cents from 1–18 years, and 1,500–2,000 IU for all adults. The best way to know your current vitamin D level is to get tested. The 25-hydroxy vitamin D test measures the amount of vitamin D in your blood so you can get a base line and go from there.

For references, please visit naturalgrocers.com/issue-93

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