Hormone Health Hub: Expert Insights on Testing, Balance & Better Living — vitamin D and hormone balance

Did you know that low vitamin D could be disrupting your sleep? Research shows that vitamin D plays a key role in serotonin and melatonin production — the hormones that regulate your sleep-wake cycle. Dr. Kate Placzek explores the science behind the vitamin D–sleep connection, what else low vitamin D affects, and how to find out if deficiency is at the root of your sleep problems.

As the days shorten and sunlight fades, four key hormonal systems come under pressure: vitamin D, serotonin, cortisol and melatonin. For those susceptible to Seasonal Affective Disorder (SAD), the disruption of these interconnected rhythms can trigger depression, fatigue, poor sleep and low mood. This article explains the science behind the SAD hormone pattern — and what you can do to support your body through the darker months.

Vitamin D has one of the most remarkable stories in nutritional science — from its discovery as the cure for rickets in the early 20th century to its emerging role in cancer prevention, heart disease, diabetes and depression. Yet a century after its identification, our understanding of vitamin D’s wider role in human health is still evolving. This article traces that history and explains why testing your vitamin D levels remains as relevant as ever.