Vitamin A is often one of the less-discussed micronutrients in relation to bone health, taking a back seat to nutrients like calcium and vitamin D. Yet this fat-soluble vitamin plays a fundamental role in skeletal development, remodeling, and mineral homeostasis. It influences gene expression in both osteoblasts and osteoclasts, and contributes to the regulation of bone turnover throughout the lifespan.

But what makes vitamin A particularly interesting, and controversial, is that its effects on bone appear to follow a double-edged pattern. While it’s essential for bone formation, several large epidemiological studies have suggested that chronically high intakes of preformed vitamin A may actually increase the risk of osteoporosis and fracture, especially when consumed as retinol from supplements or high-liver diets. And yet, the picture is not so clear-cut.

This raises compelling questions:

• Is the concern over vitamin A and bone health justified, or is it a case of context-dependent risk?
• Can vitamin A, when combined with adequate levels of D and K, actually support bone strength?
• And are there thresholds above or below which risk increases?

In this episode, we explore the human evidence on vitamin A and skeletal health, looking not only at fracture outcomes and bone mineral density data, but also at nutrient interactions, mechanistic plausibility, and the implications for supplement use in well-nourished populations.

Note: This is a Premium-exclusive episode, so you will only hear a preview on this public feed.

• [00:23] Vitamin A and bone health: an overview
• [02:50] Forms of vitamin A: retinol and carotenoids
• [04:16] Mechanisms of vitamin A in bone physiology
• [17:52] Nutrient interactions: vitamin A, D, and K
• [31:03] Practical takeaways and recommendations

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The idea that saturated fat might be harmful to our health has sparked controversy for decades. In recent years, counter-narratives have surged: suggesting that concerns over saturated fat were overblown, that LDL cholesterol doesn’t matter, or that the original diet-heart hypothesis has been debunked. These claims have become especially popular in online wellness spaces and certain dietary communities, often wrapped in compelling but misleading rhetoric.

So what does the best available evidence actually say? And how should we think about saturated fat, LDL cholesterol, and cardiovascular risk in the current day?

In this wide-ranging interview, originally recorded for the Chasing Clarity podcast, Alan and Danny explore the scientific consensus around saturated fat’s impact on blood lipids, why LDL and apoB are central to atherosclerotic disease, and how dietary patterns can meaningfully reduce risk.

Importantly, they also address some of the most persistent myths and half-truths that fuel confusion, from flawed interpretations of the Seven Countries Study to misrepresentations of newer meta-analyses.

• [03:41] How do we know saturated fat impacts LDL-C?
• [05:28] Metabolic ward studies and key findings
• [11:13] The Keys equation and subsequent research
• [17:17] Epidemiology and long-term studies
• [31:48] The Seven Countries Study
• [44:25] Understanding the impact of saturated fat on blood lipids
• [47:23] Historical and research perspectives on saturated fat
• [50:43] Practical dietary strategies for improving blood lipids
• [53:48] The Portfolio Diet and other dietary interventions
• [58:07] The role of pharmacology in managing blood lipids
• [01:00:58] Addressing misconceptions and common claims
• [01:13:57] Key ideas segment (premium-only)

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• Alan Flanagan’s Alinea Nutrition Education Hub
• Related episodes to add to your podcast queue: 532, 525, 515, 493, 481, 439

To what extent can maternal nutrition during pregnancy influence a child’s later cognitive or behavioural development?

While genetic and environmental factors are known to contribute to neurodevelopmental outcomes such as ADHD and autism, growing attention is being paid to the potential role of prenatal exposures, including dietary patterns. Yet, evidence in this area remains limited, and causality is difficult to establish.

One recent study aimed to explore this question by analysing how maternal diet quality during pregnancy (specifically, adherence to a Western-style dietary pattern) related to neurodevelopmental outcomes in children assessed clinically at age 10.

In this episode, Dr. David Horner discusses the findings from this prospective cohort study, the use of metabolic markers to complement dietary data, and the implications for future research into modifiable prenatal risk factors.

About The Guest

Dr. David Horner is a researcher in maternal nutrition and cardiometabolic health, based at the University of Copenhagen, Denmark. He is also a qualified medical doctor from Queen’s University of Belfast.

His research is driven by a keen interest in modifiable determinants of health, aiming to better understand and improve health outcomes.

Having worked as a medical doctor for 2 years in the UK, in 2017 Dr. Horner then moved to Copenhagen, where he completed a Master’s in Global Health and a PhD examining the impact of maternal dietary patterns during pregnancy on child health.

• [02:47] Introduction to the study
• [07:08] Strengths and findings of the study
• [21:17] Genetic factors and gene-environment interactions
• [25:42] Metabolomics and potential mechanisms
• [30:12] Interpreting the study’s findings
• [38:03] Future research directions
• [42:50] Key ideas segment (Sigma Nutrition Premium)

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• Email: david.horner@dbac.dk
• Study: Horner et al., 2025 – A western dietary pattern during pregnancy is associated with neurodevelopmental disorders in childhood and adolescence
• David’s LinkedIn post about the study (with discussion in the comments)