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

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 is not just a vitamin — it is a steroid hormone that plays a critical role in fertility, conception, placental development and fetal health. From improving ovulation in women with PCOS to supporting sperm motility in men, adequate vitamin D levels matter at every stage of the journey to parenthood. Discover why testing before and during pregnancy is increasingly recommended.

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.