Ode to Vitamin A

Vitamin A refers to a group of molecules called retinoids, with twenty carbon atoms linked to thirty hydrogen atoms and one oxygen atom. At the back of the eye, the retina is a layer of nerve cells sensitive to light. In these cells, a form of retinoid binds to a protein, a large molecule made of strings of molecules that fold and twist into complex shapes. This protein, now called a pigment, absorbs photons of light which trigger a nerve impulse which is sent to the optic nerve and then the brain. Most of us read these words quickly, pretending they make sense, suppressing a half-panic of questions. What is a photon and how does it start a nerve impulse and what is a nerve impulse? How does a bundle of nerve impulses variously connected to aspects of vision like color, size, depth, and brightness become a buttery-brown leather couch or an angular black walnut tree topped by the unmistakable figure of a hawk? 

We can’t hear ourselves think—we can’t process thought—at the speed of the cellular level. Still, we try to break things down, like cells do. A photon is what we have named the smallest unit of light. This “packet of energy” sometimes acts like a particle, sometimes a wave, a description already problematic. Entering the eye, the energy of a photon causes the electrons in the Vitamin A molecule to change orbit around their atom’s nucleus. Now hydrogen atoms rearrange into a new form, all happening in picoseconds, a few trillionths of a second. This new form of Vitamin A no longer fits into the protein to which it is bound, and in nanoseconds, billionths of a second, that protein changes into multiple new shapes. One of them activates another cellular protein which blocks the natural flow of positively-charged sodium ions into the cell, which changes the cell’s electrical charge, which creates the electric impulse, which travels—using an entirely different process—cell to cell to cell.

The words I am using are rough-shaped and also amorphous, suddenly not quite right, like that form of Vitamin A binding to that protein. And although we can pinpoint to some degree the where of what happens next—the electric impulse sent to the forebrain’s occipital lobe—we really have no clue as to that final question: how does this biochemistry become the image of a couch or a hawk? Nor do we understand the next step: how does the biochemistry of consciousness becomes a sentence? “That hawk every evening in the black walnut tree is the unwitting sentinel for my sorrow.” Or “No matter how much I love this buttery-brown leather couch, a sofa-futon would be more practical.”

It’s all happening without us. Nature as mysterious and secret as clouds racing across the sky, wild unknown landscapes that happen to be our own bodies, our very selves.

I began learning about Vitamin A because I am interested in hunger and the transformation of food into thought and story—more biochemistry turned to consciousness. Vitamins are how we describe any organic compound needed by the body in a small amount. We get Vitamin A or retinoids mostly from eating meat and meat products, and we get carotenoids—which our body converts to retinoids—mostly from eating green leafy vegetables and fruits colored orange, yellow, or red. How much Vitamin A we get from plants, however, is much lower than we once thought and varies based on season and preparation. Vitamin A is particularly important in the development of a human fetus and throughout childhood. We don’t always understand what Vitamin A is doing in the human body, but we do know that a lack of Vitamin A is the leading cause of preventable blindness, with a half million children going blind every year.

This is what happens. As well as morphing into the pigment that absorbs light, Vitamin A also helps produce mucous and maintain the surface of the eye and tear production. Without enough Vitamin A, you cannot cry. The mucosa membrane that covers the front of your eye and lines the inside of your eyelid becomes rough and dry and prone to infection. So does the cornea of the eye. Small holes 1-3 millimeters across, with steep sides, form at the edges of the cornea and then spread. Sometimes the cornea ruptures, liquid material of your eye escapes, and the result is a shrunken eyeball. Sometimes, the ulcerated areas are covered by white corneal scar tissue.

Half the children who go blind in this way die within a year, most from measles or diarrhea or malaria, because Vitamin A is also an important part of the immune system. This, again, is related to how Vitamin A produce mucous which protects the linings of the lungs and stomach and bowel. In truth, millions and millions of children die every year for lack of Vitamin A, whether they go blind first or not.

Eat a range of food and you’ll be fine. A carrot. An apricot. Butter. Scrambled eggs. Have a grilled cheese sandwich or vegetable soup or a kale salad. Drink mint tea. Vitamin A is a lovely molecule that fills the world and if you have access to these foods, eat them. You won’t need to worry about the pigments in your retina absorbing photons of light or the tears lubricating your eyes or weird changes in your skin and taste buds. If you are pregnant and understand that Vitamin A is essential for your child’s bone growth and development, you won’t wonder obsessively if you are seeing less well in dim light—the first sign of Vitamin A deficiency. Eat a sweet potato. Eat a fish. Eat a hamburger. Eat dinner with your family. Eat lunch with friends. Eat alone as you read a book or stare at the mountains in the distance.

Close your eyes. For a picosecond, in the darkness, biochemistry is a grace you understand.  

 One of the most depressing stories of my adult life came from a phrase coined by the environmental writer David Quammen in his 1998 essay “Planet of Weeds,” originally published in The Atlantic Monthly. Quammen’s argument was that habitat loss and degradation would result in an earth made only of scrappy, adaptable, boring “weedy” species that reproduce quickly and cohabit well with Homo sapiens, the ultimate weed. We were on our way to becoming a planet of generalists--rats, mice, cockroaches, pigeons, crows, deer, coyotes.

The future as a dirt lot, the litter of fast-food and cigarette butts, grass poking up through concrete foundations and the ground glistening with broken bottles. A place where people drank. This was my private idiosyncratic image, this planet of weeds, having bicycled or walked as a child past many dirt lots of degraded soil and Russian thistle, a definition of ugliness I felt rather than understood intellectually. No one at that time, in the mid-twentieth century, told me these dirt lots were ugly and sad. No one pointed to the arboreal majestic Sonoran Desert surrounding the sad, ugly, concrete sprawl of Phoenix, Arizona and whispered: this is the Eden you left behind and from which you are now barred by an angel carrying a fiery sword. No one needed to, I guess. It was that obvious.

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Like everyone else, I grew up in a cultural conversation, with people whispering to me all the time. Earth Day. Deep ecology. Bioregionalism. In the 1980s, my husband and I were “back-to-the-landers” in rural New Mexico, wanting to root into soil and sun, building our adobe house of mud, irrigating our way-too-big garden, milking our quickly-too-many goats, having two homebirths—a daughter and son--and too much goat cheese in the refrigerator. Our illusion that we could live off the land lasted a few weeks, or maybe a little longer. Importantly, we believed our personal connection to nature was meaningful. We believed we were part of a new environmentalism and land ethic.

Meanwhile, in the next twenty years, the cultural conversation become less about personal connection and more about apocalypse. The Age of the Anthropocene had so begun. The sixth mass extinction, ice caps melting, rainforests burning, a drumbeat of doom. Our little experiment—how many onions could we grow and what would we do with them?—seemed increasingly irrelevant. The deepening ties we felt to this watershed, our love of these hills dotted with juniper and pine—all that was nice. But the health of the planet lay in the greening of cities, where most people live, and in changing the metasystems of commerce and law. Slowly we came to the realization that we were not shaping the future. We had been left behind.

Which wasn’t so bad. Every day, in the place where I live, I feel the shock of beauty.

Clouds massing and billowing, flat-bottomed ships, cloud architecture, cloud turrets, cloud streets, weird streaks, wisps, tails, cumulus, cumulonimbus, mamma, virga. Shafts of golden light. A purity of light at the edges of a storm. Thunderclouds rising higher and higher. More light, more billowing! A view so continuously grand and mystical that the mind eventually loses interest and turns to something less extreme. 

The mourning dove, gray-cloaked, a little old-fashioned, a little Quakerly. Formerly called the Carolina pigeon, this is one of North America’s most abundant birds. Where I grew up in the suburbs of Phoenix, I often heard that plaintive coo-OO-oo…oo, oo. Coo-OO-oo…oo,oo. Coo-OO-oo…oo, oo. I am not sentimental about the suburbs of Phoenix. So I really don’t know why that coo-OO-oo heads straight for my ribcage and builds a nest there. With the slightest encouragement, I can feel weepy. Do we have some primal, aural attachment to mourning doves? Were we twins in the Creator’s womb?  

The coyote. Their lives so secretive and remote. We see a movement cross the road. We hear the distant chorus. We admire the ubiquitous, assertive scat, and we think, yes, you are still here. We have burned you alive. We have torn you apart. We have poisoned and trapped and crucified you on fences. Your response is averted. The original aikido. You slip through the interstices of home. You slip through the stories we tell about you, on your way home.

I run those same trails, on my way home, into the future. I run by hills that rise like brown wings, overgrazed for a century, a grassland dominated by mesquite and snakeweed. I run along the river running through my valley, sometimes a trickle, sometimes dry, fought over by irrigators and developers and environmentalists. I run through forests of ponderosa pine like a game of pick-up sticks, black spars and jags. Turn in a circle. The entire horizon swept by wildfires. And the aspen growing taller, scrub brush and locust, a new ecology of plants and the animals who eat them and the animals who eat them. The fire so sad and ugly to our eyes, the Earth under our feet so busy, busy.

I don’t know how to talk about the beauty of where I live--where we all live, all this land all around us, in the cities and towns surrounded by mountains and plains and rivers and oceans, in the cities themselves with their clouds and mourning doves--without sounding complacent or ignorant or autistic. As if I don’t feel the grief. The anger. The fear. Does celebrating what we have mean we stop holding on to what we are losing? So, shush about all that beauty. Don’t you see—how it is being taken away?

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My optometrist wouldn’t know a bedside manner if he had just put his book and reading glasses on it. He looks at one of my test results, does a double take, and says, “Oh. Okay! You have myasthenia gravis, an autoimmune disease. This is serious. People die.” He goes on to explain how nerve cells release the molecule acetylcholine which opens a protein called an acetylcholine receptor (another sodium channel) in a nearby muscle cell which then starts a biochemical process that signals the muscle to contract. In myasthenia gravis, the body’s immune system has mistakenly produced antibodies that interfere with this process--specifically with the acetylcholine receptor. Typically, the disease affects muscles that control the eye and eyelid, face, and throat. My symptom is double vision. But I might also start having trouble swallowing or eating or breathing. 

Time in this small brightly-lit office has become a kind of clear gel, viscous and slowing movement. This is it, I think slowly. From now on, there will be my life before this moment and my life after. Simultaneously, a part of me is distracted by amazement. All that acetylcholine being released right now, all that opening and closing, opening and closing, muscles contracting, eyes seeing, throat swallowing, heart beating. So many trillions of molecules doing just what they are supposed to do.

Later I learn that myasthenia gravis, “once a uniformly disabling and even fatal disorder,” can now be managed effectively with drugs. Likely I have ocular myasthenia gravis, confined to the muscles in my eyes, and maybe—in any case—the symptoms will continue to be mild or even disappear. That, at least, is my professional opinion. I push this to the bottom of things I worry about in the middle of the night, and since that kind of night-worry is tediously repetitive, I never get beyond the top two items.

I do occasionally find myself in conversation with protein receptors in my left eyelid. In response to acetylcholine, these bulbous shapes allow positively-charged sodium ions to enter cells which triggers the internal release of calcium ions which creates an electric current which results in movement. I have become the acetylcholine whisperer. Go, go, go, go, I say to the sodium ions. Sweetheart, I encourage that receptor. You’re doing great. Pay no attention to those antibodies.

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Sacred datura--also called jimson weed, also called devil’s weed, also called angel’s trumpet--has a large funnel-shaped, star-pointed lavender-white flower with a sweet powerful scent. This is the flower you might conjure in wizardry school if you were given that assignment: make a flower. Make something from a fairytale. Make something seductive, glamorous, sexy. Make something to make someone stop in her tracks and fall to her knees. Well, that would be Datura wrightii. Typically, the sprawling perennial forms mounds of blue-green leaves with a dozen blossoms opening in early evening and on cloudy days. Adaptable, scrappy, and not often attacked by insects and other herbivores, this weedy species likes disturbed landscapes and warm weather. Every part of the plant--leaf, petal, seed, root--is poisonous.

The chemicals in datura inhibit the transmission of acetylcholine. Your pupils dilate, your eyes are sensitive to light, your vision is blurred. Your skin is dry. Your heart is beating too fast. You can’t urinate. You have high blood pressure. Or you have low blood pressure. You may go into a coma. You may die. You may be highly agitated. You are probably delirious.

Because amazing, hard-working, best-friends-forever acetylcholine doesn’t just activate muscles. In the brain, the chemical moves, flows, quantumly entangles throughout the neural networks, specifically related to how we remember, pay attention, and make decisions. Those activities require a certain single-mindedness. They require suppressing other cortical activity, turning down the volume, in which acetylcholine has a crucial role. The absence of acetylcholine means you are being flooded instead with sensory and mental noise: memories, fantasies, subconscious images, unconscious images, and real life, too: information cross-wired, startling, leaping, pouncing, jumping, speeding through the tunnel of language, the dirt of words, lost in the silvery-buttery moonlight with a bright red scorpion like a Chinese dragon and a great stinging tail…

Unsurprisingly, people have long used datura as a source of visions and shamanic travel. Since the genus of datura can be found throughout the temperate and tropical world, the list of cultures flying to the moon on datura is a long one. For millennia, and for many of us, datura has been a spirit helper. Datura teaches. Datura lets us see the dead. Datura makes us lucky in gambling or finds a lost item or protects us from evil. Datura can heal us physically as well, curing a range of ills from asthma to skin rash.

Certain kinds of hallucinations seem specific to the suppression of acetylcholine. Often you see and hear people who are not there but uppermost in your thoughts. In parts of Mexico, the plant is called “husband-corrector,” and a woman suspecting that her husband has a mistress will sprinkle datura into his meal and observe who appears in the resulting delirium. If the wife is angry enough, she will sprinkle a lot of datura.

In summer and fall, my heart always lifts at the sight of these extravagant flowers. I think this actually happens: something in my chest moves. On its part, jimsonweed is clearly relational. Jimsonweed wants to be seen, admired, adored. Jimsonweed has something to say to me, and if that is my unconscious talking, then why not listen?

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David Quammen’s essay can still be found on the internet although I barely have the attention span to finish it now. For that I blame the internet and perhaps aging, too, perhaps a lack of acetylcholine, something about protein receptors, something about sodium ions.

I’m sixty-two years old now, extinction around the next big corner. Everything is so much more and so much less than what I thought it would be when I was a child. Slowly I am learning to love my flawed and doomed life, my very own life, which is full of miracles every nanosecond of the day. Slowing I am learning to love this planet threaded, woven, stitched with our stories, this wilderness of mourning dove and coyote, this rolling wilderness outside and inside, the wild landscapes of the body. This planet of weeds, this drumbeat of mystery, this radiance in the darkness. This planet that is so much a part of me that I cannot really tell you where it ends and where I begin.

From a short essay in Terrain.org's Letter to America series:

In the new landscape of America, with the ground shifting under our feet, we will each choose the issues more important to us. They are not competitive. I believe deeply that all these social concerns are one concern. I believe we cannot—we must not—pit national problems against international problems or tax reform against climate change or immigration policy against sexism or education against hunger. We cannot divide up the world like that or let ourselves be divided.

Because I have only so much time and resources in my personal life, I have decided to begin with one issue which I can burrow down into. One issue that I will research and know and examine thoughtfully and deeply and make my own. For many reasons, I am choosing the issue of our foreign aid to the world’s two billion poorest. I will be watching closely what happens in the area of USAID, and I will advocate for programs that do good rather than harm. I will advocate for an understanding of all our connections to the world. An understanding of our larger self-interest, as well as our moral imperative.

I will be standing right next to people who have chosen other issues equally central to what needs to be done today. I see us all standing together now, shoulder to shoulder, not competing with each other but raising one voice, one song with many harmonies. Or, to use another metaphor—in Malawi, there is a saying: Mutu umodzi susenza denga. One head cannot hold up a roof. In the building of a home, the last step is for a group of villagers to lift up together the thatched roof onto the walls of burnt-mud bricks.