Executive summary
Neurologist Dr. Nasha Gmanac, speaking on The Diary Of A CEO, connects vitamin D to sleep quality and REM sleep through its role in acetylcholine production. Separately, Andrew Huberman on the Huberman Lab podcast discussed non-stimulant strategies for evening exercise, including alpha-GPC and vagus nerve breathing techniques. Physicians on the drsuneeldhand podcast highlighted how hospital nutrition choices—including protein intake and processed food—can influence recovery and healing.
Key takeaways
- Dr. Nasha Gmanac (The Diary Of A CEO) suggests vitamin D may influence sleep quality through its role in producing acetylcholine, a calming neurotransmitter tied to REM and deep sleep.
- Andrew Huberman (Huberman Lab) recommends physiological sigh breathing and post-workout hot showers as non-stimulant ways to lower cortisol and support sleep after evening exercise.
- Physicians on drsuneeldhand emphasize that whole-food nutrition—balanced protein and produce—may support the body's healing and recovery processes, especially during illness.
YOUR DAILY WELLNESS FOCUS
Good morning. Today, we're gently exploring how your sleep, your nervous system, and the food on your plate are more connected than they might seem. From the biochemistry of restful sleep to the way your body processes stress after a workout or a busy day, small, intentional choices can help you feel more grounded. Let's look at a few evidence-informed ideas you can hold lightly and explore at your own pace.
KEY INSIGHTS FOR YOUR WELLBEING
You might find it interesting that sleep quality may have more to do with biochemistry than bedtime rituals alone. According to Dr. Nasha Gmanac on The Diary Of A CEO, vitamin D functions more like a hormone than a traditional vitamin—it's made in your skin through sunlight exposure rather than primarily absorbed from food. Dr. Gmanac explained that vitamin D appears to support production of an enzyme that creates acetylcholine, a brain chemical involved in the 'rest and digest' nervous system that she says governs deep, restorative sleep and REM sleep (the dream stage associated with memory consolidation and mood regulation). She noted that reduced sun exposure since the 1980s—due to more indoor living, sunscreen use, and air conditioning—may be an underrecognized factor behind widespread sleep struggles. Interestingly, acetylcholine also came up in a separate conversation. According to Andrew Huberman on the Huberman Lab podcast, a supplement called alpha-GPC raises acetylcholine levels and, in research he referenced, has been shown to modestly increase REM sleep without reducing deep sleep—unlike classic stimulants such as caffeine. Huberman also described the 'physiological sigh,' a breathing pattern of two inhales through the nose followed by a long exhale, as a way to activate the calming, brain-to-body branch of the vagus nerve, which he said can help bring cortisol (a stress hormone) back down after an intense workout or a stressful moment. Nutrition also plays a supporting role in how your body recovers and regulates stress. On the drsuneeldhand podcast, Dr. Ben and Dr. Peter discussed how ultra-processed, sugary foods can spike glucose, insulin, and cortisol in ways that may slow healing—particularly relevant for anyone recovering from illness or surgery. They pointed to albumin, a blood marker of protein status, as one clinical indicator connected to recovery outcomes, and emphasized that whole-food carbohydrates (fruits, vegetables) differ meaningfully from heavily processed ones. Finally, a conversation on the Chris Williamson podcast touched on why even positive milestones—like winning a championship—can feel less satisfying than expected, a pattern researchers call the 'arrival fallacy.' The speakers suggested that noticing when we're mentally rushing ahead to the 'next thing' rather than staying present may be a gentle first step toward more contentment, whether that's after a health milestone or an ordinary day.
ACTIONABLE STEPS FOR TODAY
1. **Get natural sunlight on your skin, if safe for you.** Even 10–15 minutes outdoors, especially earlier in the day, may support your body's natural vitamin D production, which Dr. Gmanac connects to sleep-regulating brain chemistry. If you have sun sensitivity or skin concerns, check with your dermatologist first. 2. **Build meals around protein and colorful produce.** Following the general philosophy shared by Dr. Ben and Dr. Peter, try aiming for a balance of protein (like eggs, fish, chicken, or legumes) alongside fruits and vegetables, while gently minimizing heavily processed snacks. This isn't about strict rules—just a supportive shift toward whole foods. 3. **Try a few rounds of physiological sighing when you feel wound up.** As described by Andrew Huberman, two inhales through the nose followed by one long exhale may help calm your nervous system, whether after exercise, a stressful meeting, or before bed. 4. **If you exercise in the evening, consider a hot shower afterward.** Huberman noted this can support the natural drop in core body temperature that helps prepare your body for sleep. 5. **Practice noticing 'arrival fallacy' moments.** When you complete a goal or task, pause and notice if your mind immediately jumps to the next thing. Gently bringing your attention back to the present, as discussed on the Chris Williamson podcast, may support a greater sense of contentment over time.
A NOTE ON SAFETY
This briefing is intended for educational purposes and is not a substitute for personalized medical advice. Vitamin D levels, sleep patterns, and nutritional needs vary significantly from person to person, so it's worth discussing vitamin D testing with your doctor before starting any supplementation, especially since excessive vitamin D intake can cause harm. If you're considering alpha-GPC or any new supplement, know that Huberman flagged a potential link between high-dose, frequent use and elevated TMAO, a compound associated with cardiovascular risk—this is worth reviewing with your provider, particularly if you have existing heart health concerns. If you experience persistent insomnia, significant daytime fatigue, unexplained mood changes, or symptoms of malnutrition (unintended weight loss, weakness, slow wound healing), please schedule a visit with your healthcare provider. Anyone managing a chronic condition, recovering from surgery, or taking medications should consult their care team before making dietary or supplement changes discussed here.
Sources
- The Diary Of A CEO (Dr. Nasha Gmanac)
- drsuneeldhand (Dr. Ben and Dr. Peter)
- Huberman Lab (Andrew Huberman)
- Chris Williamson podcast