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How Children Grow Taller
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In one pass A child grows taller as the bones of the legs and spine slowly get longer, and bones get longer in only one place: the growth plates at each end.
Educational content, not medical advice — consult a clinician.
Story path
Chapter 1
Bones lengthen at the growth plates
A child grows taller as the bones of the legs and spine slowly get longer, and bones get longer in only one place: the growth plates at each end.
A growth plate is a layer of cartilage sandwiched near each end of a long bone. Its cartilage cells first divide and line up in stacks, then swell to a much larger size; that cartilage is then replaced by bone, and the bone extends a little further (Baron 2015). Gaining height means this layer keeps making new cartilage and keeps turning it into bone.
The layer does not work forever. The reserve cells inside it can divide only a limited number of times and slow down as they are used up, which is why older children grow more slowly. At the end of puberty the whole layer is replaced by bone, a step called epiphyseal fusion, and from then on the bone cannot get longer (Nilsson 2004).
So how much more a child can grow depends on two things: how long the growth plates stay open, and how good their working conditions are in the meantime. The chapters that follow are about those conditions. If a child's height keeps sliding down the growth chart, or they are much shorter than children their age, the chapter When to take a child to a doctor lists the situations that need a doctor.
A growth plate is a layer of cartilage sandwiched near each end of a long bone. Its cartilage cells first divide and line up in stacks, then swell to a much larger size; that cartilage is then replaced by bone, and the bone extends a little further (Baron 2015). Gaining height means this layer keeps making new cartilage and keeps turning it into bone.
The layer does not work forever. The reserve cells inside it can divide only a limited number of times and slow down as they are used up, which is why older children grow more slowly. At the end of puberty the whole layer is replaced by bone, a step called epiphyseal fusion, and from then on the bone cannot get longer (Nilsson 2004).
So how much more a child can grow depends on two things: how long the growth plates stay open, and how good their working conditions are in the meantime. The chapters that follow are about those conditions. If a child's height keeps sliding down the growth chart, or they are much shorter than children their age, the chapter When to take a child to a doctor lists the situations that need a doctor.
Mechanism · How cartilage turns into bone
Under a microscope, a growth plate is organized into three layers running from the end of the bone toward the shaft (Baron 2015):Resting zone: a group of quiet reserve cells, the seed stock of the whole plate.Proliferative zone: the cells start dividing, and the new cells line up in columns along the long axis of the bone. The direction of these columns is why a bone grows longer rather than wider.Hypertrophic zone: the cells stop dividing, swell up, and secrete cartilage matrix.
Blood vessels and bone-forming cells then invade the swollen cartilage and rebuild it into real bone, a process called endochondral ossification.
Why does a bone grow more and more slowly? One explanation is that the reserve cells of the resting zone can divide only a limited number of times, so each batch used up leaves fewer behind and the plate gradually ages on its own; the evidence for this comes mainly from animal studies (Nilsson 2004). Once a plate has fused, the cartilage is gone, so after that nothing a person eats or does can make the bone longer.
What happens to these layers during training and injury is covered in more detail in Youth training.
Chapter 2
Growth hormone follows deep sleep
The main signal that drives the growth plates is growth hormone. Its largest release of the day follows the first stretch of deep sleep after falling asleep, not the clock.
Growth hormone is released by the pituitary gland at the base of the brain, in bursts rather than a steady stream. Part of its effect is direct, on the growth plates; part comes through the liver, which it prompts to make a second growth signal, insulin-like growth factor 1 (), that travels in the blood to the plates. The growth plates also make some IGF-1 on the spot (Baron 2015).
The link between growth hormone and sleep comes from two small studies in young adults. The growth hormone peak appeared on entering deep sleep, and when sleep was delayed, the peak was delayed too (Takahashi 1968). When the times of sleeping and waking were reversed by a full 12 hours, the peak still followed sleep (Sassin 1969).
The mechanism predicts that what matters for growing is enough sleep and deep sleep, not a set bedtime such as asleep before ten at night. The step from sleep to final height has not been measured directly in children.
Growth hormone is released by the pituitary gland at the base of the brain, in bursts rather than a steady stream. Part of its effect is direct, on the growth plates; part comes through the liver, which it prompts to make a second growth signal, insulin-like growth factor 1 (), that travels in the blood to the plates. The growth plates also make some IGF-1 on the spot (Baron 2015).
The link between growth hormone and sleep comes from two small studies in young adults. The growth hormone peak appeared on entering deep sleep, and when sleep was delayed, the peak was delayed too (Takahashi 1968). When the times of sleeping and waking were reversed by a full 12 hours, the peak still followed sleep (Sassin 1969).
The mechanism predicts that what matters for growing is enough sleep and deep sleep, not a set bedtime such as asleep before ten at night. The step from sleep to final height has not been measured directly in children.
Evidence · What the two sleep studies measured
Takahashi 1968 monitored 8 young adults over a total of 38 nights, drawing blood every 30 minutes while recording brain waves and eye movements.In 7 of the 8, a growth hormone peak lasting 1.5 to 3.5 hours appeared on entering deep sleep, with occasional smaller peaks in later deep sleep.When falling asleep was delayed, the peak was delayed; people woken for 2 to 3 hours who then went back to sleep had another peak.The peak had nothing to do with changes in blood glucose, insulin or cortisol.
Sassin 1969 reversed the times at which the volunteers slept and woke by a full 12 hours, and growth hormone release during sleep reversed with them. So the release does not run on the time of day; it follows sleep, especially slow-wave sleep, the deepest stage, when brain waves are slowest.
Know the limits: both studies had only a few adults and measured a hormone in the blood, not height. Nobody has tested whether short sleep makes children shorter as adults. How sleep is divided into stages, and why deep sleep is concentrated early in the night, is covered in Sleep architecture and sleep debt.
Chapter 3
Parents' heights give a range
How tall a child ends up is decided mostly by genes, but the parents' heights give only a range, not a number.
An analysis pooling 45 twin cohorts from 20 countries found that the younger the children, the more the environment a family shares (what they eat, what illnesses they have had) explains differences in height. With age the genetic share grows, peaking in adolescence, when it explains about 83% of the differences in boys and about 76% in girls (Jelenkovic 2016). This describes why a group of children differ in height; it does not say how much of any one child's height is fixed. Height is shaped by hundreds of genes, and most of them sit outside the growth hormone pathway and act directly on the cartilage cells of the growth plate (Baron 2015).
Doctors use the parents' heights to work out a child's mid-parental target height. The UK growth chart from the Royal College of Paediatrics and Child Health states that about 4 children in 5 end up with an adult height within 7 cm above or below this target.
So short parents do not mean a short child. But if a child's height is clearly below the range the parents' heights predict, it is worth having a doctor take a look.
An analysis pooling 45 twin cohorts from 20 countries found that the younger the children, the more the environment a family shares (what they eat, what illnesses they have had) explains differences in height. With age the genetic share grows, peaking in adolescence, when it explains about 83% of the differences in boys and about 76% in girls (Jelenkovic 2016). This describes why a group of children differ in height; it does not say how much of any one child's height is fixed. Height is shaped by hundreds of genes, and most of them sit outside the growth hormone pathway and act directly on the cartilage cells of the growth plate (Baron 2015).
Doctors use the parents' heights to work out a child's mid-parental target height. The UK growth chart from the Royal College of Paediatrics and Child Health states that about 4 children in 5 end up with an adult height within 7 cm above or below this target.
So short parents do not mean a short child. But if a child's height is clearly below the range the parents' heights predict, it is worth having a doctor take a look.
In practice · How to read a child's growth chart
Each line on a growth chart is a centile. A child on the 50th centile sits roughly in the middle of 100 children of the same age and sex; on the 2nd centile, only about 2 of those children are shorter.One centile space: the distance between two neighboring centile lines. Healthy children mostly keep to their own space and do not cut across several lines.Compare with the parents: plot both parents' heights on the scale beside the chart and join them with a line to get the child's mid-parental centile. The UK chart states that 9 children in 10 have a height centile within two spaces above or below it, and only about 1% fall more than three spaces below.Measure accurately: shoes off, standing straight against a wall, using a fixed height measure. One measurement says little; several joined up over time show the trend.
This method comes from the UK growth charts (RCPCH) and the standards of the UK society of pediatric endocrinologists (BSPED). Other countries use their own growth charts, but reading centiles and trends works the same way.
Chapter 4
Eating enough to grow
Nutrition works on height more like a threshold: without enough food the growth plates slow down, but once a child eats enough, eating more does not make the bones grow longer.
Children who do not get enough to eat often have normal or even high growth hormone in their blood, yet grow slowly: when energy and protein are short, and other growth signals are turned down, and the limited supply goes first to keeping the body alive (Baron 2015). Zinc has a similar threshold. Pooling 33 randomized trials, extra zinc made children grow a bit taller, and the effect showed up mainly in children who were already short, thin or likely short of zinc (Brown 2002).
Calcium and vitamin D mainly decide how hard the bones are. A severe shortage causes rickets: the growth plates cannot mineralize, the legs bow, the wrists and ankles thicken, and growth slows (Munns 2016). But extra calcium adds bone mass, not height. In a randomized trial in 7-year-old Chinese children who usually ate very little calcium, 18 months of calcium raised bone mineral content more, and growth in height did not differ (Lee 1994). Trials have also measured what milk does for height, and the effect is small (Hidayat 2023).
So the job is to eat enough and eat a varied diet. Whether to add zinc or calcium is for a doctor to decide after tests.
Children who do not get enough to eat often have normal or even high growth hormone in their blood, yet grow slowly: when energy and protein are short, and other growth signals are turned down, and the limited supply goes first to keeping the body alive (Baron 2015). Zinc has a similar threshold. Pooling 33 randomized trials, extra zinc made children grow a bit taller, and the effect showed up mainly in children who were already short, thin or likely short of zinc (Brown 2002).
Calcium and vitamin D mainly decide how hard the bones are. A severe shortage causes rickets: the growth plates cannot mineralize, the legs bow, the wrists and ankles thicken, and growth slows (Munns 2016). But extra calcium adds bone mass, not height. In a randomized trial in 7-year-old Chinese children who usually ate very little calcium, 18 months of calcium raised bone mineral content more, and growth in height did not differ (Lee 1994). Trials have also measured what milk does for height, and the effect is small (Hidayat 2023).
So the job is to eat enough and eat a varied diet. Whether to add zinc or calcium is for a doctor to decide after tests.
Evidence · What zinc, calcium and milk trials found
Zinc (Brown 2002): a of 33 randomized trials found an effect on growth in height of 0.35 standard deviations. The effect was clearer in children who were thin to begin with and, from 6 months of age, short. The authors' advice targets populations at high risk of zinc deficiency where stunted growth is common, not all children.Calcium (Lee 1994): 162 seven-year-old Chinese children who usually ate little calcium were randomly given calcium tablets or a placebo. After 18 months, bone mineral content in the radius of the forearm rose by 16.5% in the calcium group and by 13.97% in the control group; growth in height did not differ between the groups.Dairy (de Beer 2012): pooling 12 controlled trials, the most likely effect was about 0.4 cm of extra growth a year for roughly 245 mL more milk a day, with a larger effect in children who were short to begin with and in teenagers. Many trials were not randomized and many were old, and the author rated the evidence as moderate quality.Dairy (Hidayat 2023): a newer pooling of randomized trials, 15 of which measured height, found 0.21 cm more height in the dairy groups and higher in the blood. The authors read this as fitting the growth-promoting effect of protein, and called the improvement in bone mass very small.Taken together: calcium tablets add bone mass; milk, which brings protein, nudges IGF-1 and height up a little; zinc shows an effect only in children short of zinc. The gains in these trials are small and concentrated in children who were underfed or growing slowly.
de-beer-2012-dairy-stature
Chapter 5
The puberty spurt and closing plates
Puberty is when children grow fastest, and also when the growth plates begin to close. What closes them is estrogen, in boys and girls alike.
In data on American children, girls start to speed up at about 9 on average and boys at about 11. Over the whole of puberty, girls grow about 27.5 to 29 cm and boys about 30 to 31 cm (Abbassi 1998).
Boys have estrogen too; the body makes it from testosterone. A man whose estrogen receptor did not work went through an otherwise normal puberty, yet at 28 he was still growing taller, at 204 cm, with growth plates that had not fused (Smith 1994). Rare cases like this show that the final closing of the plates depends on estrogen. Estrogen speeds up the using-up of the reserve cells in the growth plate, so the plate ages sooner (Baron 2015).
That is why puberty that comes too early also closes the growth plates early, and adult height may suffer. Signs of puberty before age 8 in girls or before age 9 in boys (breast development, pubic hair, enlarging testicles) mean a child should see a doctor (Latronico 2016).
In data on American children, girls start to speed up at about 9 on average and boys at about 11. Over the whole of puberty, girls grow about 27.5 to 29 cm and boys about 30 to 31 cm (Abbassi 1998).
Boys have estrogen too; the body makes it from testosterone. A man whose estrogen receptor did not work went through an otherwise normal puberty, yet at 28 he was still growing taller, at 204 cm, with growth plates that had not fused (Smith 1994). Rare cases like this show that the final closing of the plates depends on estrogen. Estrogen speeds up the using-up of the reserve cells in the growth plate, so the plate ages sooner (Baron 2015).
That is why puberty that comes too early also closes the growth plates early, and adult height may suffer. Signs of puberty before age 8 in girls or before age 9 in boys (breast development, pubic hair, enlarging testicles) mean a child should see a doctor (Latronico 2016).
Evidence · Early or late developers: who ends up taller
In the American data pooled by Abbassi 1998, the year of fastest growth comes at about 11.5 for girls, at about 8.3 cm in that year, and at about 13.5 for boys, at about 9.5 cm.Children whose spurt starts early grow more during puberty, and those who start late grow somewhat less. But the age at which the spurt starts is not linked to final height. So within the normal range, a child who shoots up a few years early will not necessarily end up taller, and a late developer is often just arriving later, not failing to grow.
Outside the normal range is a different matter. Morishima 1995 reported a sister and brother who could not convert androgens into estrogen. At 24 the brother had a bone age of only 14 and stood 204 cm tall: without estrogen, the growth plates stay open. In the other direction, puberty that comes too early closes the plates early.
Some parents want shots that hold back puberty for a child whose puberty is on time, hoping for a few extra centimeters. A consensus of European and North American experts states that these drugs (GnRH analogs) clearly raise adult height only in central precocious puberty that starts very early (girls under 6). Their use in other situations still needs research and cannot be recommended routinely (Carel 2009). Whether to use them is for a pediatric endocrinologist to judge.
morishima-1995-aromatase-deficiency
Chapter 6
Height products and popular claims
No reliable trial shows that height pills, height supplements or height insoles make a child end up taller. What makes children grow is still the handful of things in the chapters above.
Height supplements: these are mostly calcium, zinc and assorted amino acids. As the nutrition chapter showed, extra calcium adds bone mass, and zinc shows an effect only in children short of zinc, which only a test can tell.Products taken by mouth that claim to contain growth hormone: growth hormone is a protein, and swallowed it is broken down in the gut like any other protein, which is why doctors can give it only by injection.Height pills of unknown origin: if one were secretly spiked with sex hormones, the mechanism predicts it would close the growth plates early instead; this step has not been measured directly.Stretching, hanging from a bar, and height insoles: everyone gets a little taller and shorter over a day. In one study, 8 young adults varied by about 19.3 mm between morning and evening; more than half of the loss came in the first hour after getting up, and it returned while lying down at night (Tyrrell 1985). That is the discs in the spine squashing and springing back; the bones do not get longer. Insoles just raise the shoe.Lifting weights stunts growth: in controlled strength-training trials in children, growth in height was not affected (Malina 2006); Youth training covers this in detail.
Height supplements: these are mostly calcium, zinc and assorted amino acids. As the nutrition chapter showed, extra calcium adds bone mass, and zinc shows an effect only in children short of zinc, which only a test can tell.Products taken by mouth that claim to contain growth hormone: growth hormone is a protein, and swallowed it is broken down in the gut like any other protein, which is why doctors can give it only by injection.Height pills of unknown origin: if one were secretly spiked with sex hormones, the mechanism predicts it would close the growth plates early instead; this step has not been measured directly.Stretching, hanging from a bar, and height insoles: everyone gets a little taller and shorter over a day. In one study, 8 young adults varied by about 19.3 mm between morning and evening; more than half of the loss came in the first hour after getting up, and it returned while lying down at night (Tyrrell 1985). That is the discs in the spine squashing and springing back; the bones do not get longer. Insoles just raise the shoe.Lifting weights stunts growth: in controlled strength-training trials in children, growth in height was not affected (Malina 2006); Youth training covers this in detail.
Clinical · Who growth hormone shots are for
Growth hormone shots are a real medicine, used for growth problems with an identified cause, such as a body that cannot make enough growth hormone of its own. Whether and how to use them is decided by a pediatric endocrinologist after testing.Some children are simply short with no cause found, which is called idiopathic short stature. A systematic review pooled 3 randomized trials in such children, 115 children in all: those given growth hormone ended up about 4 cm taller as adults than the controls on average, and 7 non-randomized trials gave about 3 cm. The authors note that this is less than the effect in the conditions the drug is approved for, and that the response varies a great deal from child to child (Deodati 2011).
So it is not a shortcut to a few extra centimeters for a healthy child. Whether a child is truly short and whether there is a cause comes first: see a doctor using the lines in the chapter When to take a child to a doctor. Whether a short child with no cause found should use this kind of drug is a decision to weigh together with a pediatric endocrinologist.
deodati-2011-gh-idiopathic-short-stature
Chapter 7
When to take a child to a doctor
Most children who are on the short side are healthy: their family is not tall, or they are simply developing later. In the situations below, it is worth taking a child to a pediatrician or a pediatric endocrinologist.
Height itself:
Height below the 0.4th centile for age and sex, that is, among the shortest 4 of every 1000 children.A height centile more than 3 centile spaces below the centile predicted from the parents' heights.Height dropping down the chart by more than 1 centile space (once a measuring error has been ruled out).A sudden surge in height that crosses centile lines upward before the age of puberty.
The timing of puberty:
Signs of puberty before age 8 in girls or before age 9 in boys: breast development, pubic hair, enlarging testicles.No sign of puberty at all by age 13 in girls or age 14 in boys.
See a doctor sooner if any of these come with it: weight loss, long-lasting diarrhea or constipation, repeated headaches or vomiting, anemia, body proportions that look out of balance, or signs of an underactive thyroid such as always feeling cold and lacking energy.
These lines come from the UK growth charts of the Royal College of Paediatrics and Child Health and the referral standards of the UK society of pediatric endocrinologists (BSPED). Growth charts differ from country to country, but the reasoning is the same. This story is education and does not replace a diagnosis.
Height itself:
Height below the 0.4th centile for age and sex, that is, among the shortest 4 of every 1000 children.A height centile more than 3 centile spaces below the centile predicted from the parents' heights.Height dropping down the chart by more than 1 centile space (once a measuring error has been ruled out).A sudden surge in height that crosses centile lines upward before the age of puberty.
The timing of puberty:
Signs of puberty before age 8 in girls or before age 9 in boys: breast development, pubic hair, enlarging testicles.No sign of puberty at all by age 13 in girls or age 14 in boys.
See a doctor sooner if any of these come with it: weight loss, long-lasting diarrhea or constipation, repeated headaches or vomiting, anemia, body proportions that look out of balance, or signs of an underactive thyroid such as always feeling cold and lacking energy.
These lines come from the UK growth charts of the Royal College of Paediatrics and Child Health and the referral standards of the UK society of pediatric endocrinologists (BSPED). Growth charts differ from country to country, but the reasoning is the same. This story is education and does not replace a diagnosis.
References · 17
- Baron, J., Sävendahl, L., De Luca, F., Dauber, A., Phillip, M., Wit, J. M., & Nilsson, O. (2015). Short and tall stature: a new paradigm emerges. Nature Reviews Endocrinology, 11(12), 735-746. Narrative review. Height gain is driven by chondrogenesis in the growth plate, which has resting, proliferative and hypertrophic zones; chondrocytes proliferate, hypertrophy and secrete matrix, and the new cartilage is remodelled into bone. The GH-IGF-1 axis is just one of many systems regulating the growth plate: GH acts through circulating IGF-I and locally, in part through local IGF-I production. Longitudinal growth is regulated by nutritional intake through leptin, IGF-I, sex steroids, thyroid hormone and glucocorticoids; undernourished children have impaired linear growth despite elevated GH levels, whereas obese children grow normally or slightly faster despite low GH. Estrogen accelerates loss of resting-zone progenitor cells and so the senescence of the growth plate. A GWAS meta-analysis identified 423 loci for adult height, mostly outside the GH-IGF-1 axis (full text, PMC5002943). 10.1038/nrendo.2015.165
- Nilsson, O., & Baron, J. (2004). Fundamental limits on longitudinal bone growth: growth plate senescence and epiphyseal fusion. Trends in Endocrinology and Metabolism, 15(8), 370-374. Review. Longitudinal bone growth is rapid early in life, then slows and ceases; the decline is caused mainly by a falling rate of chondrocyte proliferation. This programmed senescence appears intrinsic to the growth plate rather than hormonal, possibly because stem-like resting-zone cells have a finite proliferative capacity that is gradually exhausted. In humans, proliferative exhaustion is followed by epiphyseal fusion, in which growth plate cartilage is replaced completely by bone. Much of the mechanistic evidence is from animals. 10.1016/j.tem.2004.08.004
- Royal College of Paediatrics and Child Health. (2013). UK growth chart 2-18 years (girls and boys charts, issue 2). Further assessment is advised if height is below the 0.4th centile, if the height centile is more than 3 centile spaces below the mid-parental centile, or if height drops by more than 2 centile spaces once measurement error is excluded; a centile space is the distance between two centile lines. Most children's height centiles (nine out of ten) are within two centile spaces of the mid-parental centile, and only 1 percent are more than three spaces below. Four children out of five have an adult height within ±7 cm of the mid-parental target height. Puberty before 8 years in girls or 9 years in boys is likely to be precocious, and no signs of puberty by 13 years in girls or 14 years in boys is delayed; both need further assessment. Remove shoes and measure with a correctly installed stadiometer. www.rcpch.ac.uk/sites/default/files/Girls_2-18_years_growth_chart.pdf
- Takahashi, Y., Kipnis, D. M., & Daughaday, W. H. (1968). Growth hormone secretion during sleep. The Journal of Clinical Investigation, 47(9), 2079-2090. Plasma GH was measured every 30 min with EEG on 38 nights in eight young adults. In seven, a GH peak lasting 1.5-3.5 h appeared with the onset of deep sleep; smaller peaks sometimes followed in later deep sleep. The peak was delayed when sleep onset was delayed, and subjects woken for 2-3 h who went back to sleep had another peak. The peak was unrelated to glucose, insulin or cortisol. Small physiological study in adults; it did not measure growth. 10.1172/JCI105893
- Sassin, J. F., Parker, D. C., Mace, J. W., Gotlin, R. W., Johnson, L. C., & Rossman, L. G. (1969). Human growth hormone release: relation to slow-wave sleep and sleep-waking cycles. Science, 165(3892), 513-515. GH release during sleep is related to slow, synchronized (slow-wave) sleep; when the sleep-waking cycle was reversed by 12 hours, sleep-related GH release reversed with it, so the release does not follow a circadian rhythm independent of sleep. Small physiological study in adults. 10.1126/science.165.3892.513
- Jelenkovic, A., Sund, R., Hur, Y.-M., Yokoyama, Y., Hjelmborg, J. v. B., Möller, S., et al., & Silventoinen, K. (2016). Genetic and environmental influences on height from infancy to early adulthood: An individual-based pooled analysis of 45 twin cohorts. Scientific Reports, 6, 28496. Pooled 45 twin cohorts from 20 countries, 180,520 paired measurements at ages 1-19 years. Shared environmental factors explained the largest share of height variation in early childhood, and their effect remained until early adulthood; the relative genetic contribution rose with age and was greatest in adolescence (up to 0.83 in boys and 0.76 in girls). Genetic variance was greatest in North America and Australia and lowest in East Asia, but the relative genetic proportion was roughly similar across regions. Heritability describes variation within these populations, not one child. 10.1038/srep28496
- Brown, K. H., Peerson, J. M., Rivera, J., & Allen, L. H. (2002). Effect of supplemental zinc on the growth and serum zinc concentrations of prepubertal children: a meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition, 75(6), 1062-1071. Meta-analysis of 33 randomized trials. Zinc supplementation produced significant positive responses in height increments (effect size 0.350 SD, 95% CI 0.189-0.511) and weight increments (0.309), with no effect on weight-for-height. Growth responses were greater in children with low initial weight-for-age and, above age 6 months, low initial height-for-age. The authors conclude zinc programs should be considered in populations at risk of zinc deficiency, especially where underweight or stunting is common. 10.1093/ajcn/75.6.1062
- Munns, C. F., Shaw, N., Kiely, M., Specker, B. L., Thacher, T. D., Ozono, K., et al. (2016). Global consensus recommendations on prevention and management of nutritional rickets. The Journal of Clinical Endocrinology & Metabolism, 101(2), 394-415. GRADE-based consensus of 33 experts from 11 organisations. Nutritional rickets is a disorder of defective chondrocyte differentiation and mineralization of the growth plate and defective osteoid mineralization, caused by vitamin D and/or calcium deficiency; it affects health, growth and development. Signs include swelling of wrists and ankles, leg deformity (bow legs or knock knees), rachitic rosary, delayed fontanelle closure, hypocalcemic seizures and failure to thrive. Low dietary calcium raises rickets risk independent of vitamin D status. 10.1210/jc.2015-2175
- Lee, W. T., Leung, S. S., Wang, S. H., Xu, Y. C., Zeng, W. P., Lau, J., Oppenheimer, S. J., & Cheng, J. C. (1994). Double-blind, controlled calcium supplementation and bone mineral accretion in children accustomed to a low-calcium diet. The American Journal of Clinical Nutrition, 60(5), 744-750. Randomized, double-blind 18-month trial in 162 seven-year-old Chinese children with habitually low calcium intakes. The supplemented group gained significantly more radial bone mineral content (16.5% vs 13.97%) and BMC/bone width than controls, but there was no effect on height increment. Whether the higher bone mass is maintained was not known. 10.1093/ajcn/60.5.744
- Hidayat, K., Zhang, L.-L., Rizzoli, R., Guo, Y.-X., Zhou, Y., Shi, Y.-J., Su, H.-W., Liu, B., & Qin, L.-Q. (2023). The effects of dairy product supplementation on bone health indices in children aged 3 to 18 years: a meta-analysis of randomized controlled trials. Advances in Nutrition, 14(5), 1187-1196. Meta-analysis of 21 publications of randomized trials. Dairy supplementation slightly increased whole-body and regional bone mineral content and density and height (0.21 cm, 95% CI 0.09-0.34; 15 trials), raised serum IGF-I and lowered parathyroid hormone. The authors note the magnitude of the bone improvement was very small, and read the IGF-I rise as consistent with the anabolic effect of protein. 10.1016/j.advnut.2023.06.010
- Abbassi, V. (1998). Growth and normal puberty. Pediatrics, 102(2 Pt 3), 507-511. Review of published growth data in American children. Mean take-off age of the pubertal spurt is about 11 years in boys and 9 years in girls; peak height velocity comes at a mean 13.5 and 11.5 years, with whole-year peak velocity of 9.5 cm/y in boys and 8.3 cm/y in girls. Pubertal growth contributes about 30-31 cm in boys (17-18% of final height) and 27.5-29 cm in girls (17%). The size of pubertal growth correlates negatively with take-off age but not with final height. pubmed.ncbi.nlm.nih.gov/9685454
- Smith, E. P., Boyd, J., Frank, G. R., Takahashi, H., Cohen, R. M., Specker, B., Williams, T. C., Lubahn, D. B., & Korach, K. S. (1994). Estrogen resistance caused by a mutation in the estrogen-receptor gene in a man. The New England Journal of Medicine, 331(16), 1056-1061. A 28-year-old man with a disruptive estrogen-receptor mutation was tall (204 cm) with incomplete epiphyseal closure and continued linear growth into adulthood despite otherwise normal puberty and normal testosterone; bone density was low and he did not respond to estrogen. Conclusion: estrogen is important for bone maturation and mineralization in men as well as women. Single case. 10.1056/NEJM199410203311604
- Latronico, A. C., Brito, V. N., & Carel, J.-C. (2016). Causes, diagnosis, and treatment of central precocious puberty. The Lancet Diabetes & Endocrinology, 4(3), 265-274. Review. Central precocious puberty results from premature activation of the hypothalamic-pituitary-gonadal axis, mimicking normal puberty at an inappropriate age: before 8 years in girls and 9 years in boys. It can follow brain malformations or injuries, but in most girls the cause is unknown; MKRN3 defects occur in familial cases. GnRH agonists are the standard treatment. 10.1016/S2213-8587(15)00380-0
- Carel, J.-C., Eugster, E. A., Rogol, A., Ghizzoni, L., Palmert, M. R., ESPE-LWPES GnRH Analogs Consensus Conference Group, et al. (2009). Consensus statement on the use of gonadotropin-releasing hormone analogs in children. Pediatrics, 123(4), e752-e762. Thirty experts from North America and Europe. The efficacy of GnRH analogs in increasing adult height is undisputed only in early-onset central precocious puberty (girls under 6 years). Few controlled prospective studies exist and many conclusions rely on expert opinion. Use of GnRH analogs for conditions other than central precocious puberty requires further investigation and cannot be suggested routinely. 10.1542/peds.2008-1783
- Tyrrell, A. R., Reilly, T., & Troup, J. D. (1985). Circadian variation in stature and the effects of spinal loading. Spine, 10(2), 161-164. Stature measured to 1 mm in eight young adults: mean daily variation 19.3 mm (1.1% of stature); 54% of the daytime loss occurred in the first hour after rising and about 70% was regained in the first half of the night. Loading the spine increased shrinkage. Small physiological study in adults. 10.1097/00007632-198503000-00011
- Malina, R. M. (2006). Weight training in youth — growth, maturation, and safety: an evidence-based review. Clinical Journal of Sport Medicine, 16(6), 478-487. Review of 22 experimental training studies in pre- and early-pubertal youth, mostly 8- and 12-week programmes: strength rose and was lost with detraining; the programmes did not influence growth in height and weight; only 10 studies monitored injuries (3 reported). Supervised programmes with low instructor-to-participant ratios were relatively safe. These are short trials, not long-term follow-up of stature or growth plates (abstract, PMID 17119361). 10.1097/01.jsm.0000248843.31874.be
- British Society for Paediatric Endocrinology and Diabetes, Growth Disorders Special Interest Group. (2021). Clinical standards for growth assessment and referral criteria for children with a suspected growth disorder. UK guidance recommends referral for height below the 0.4th centile (-2.67 SDS). Additional criteria for growth assessment: height centile more than 3 centile spaces (>2.0 SDS) below the mid-parental centile and/or a drop in height of more than 1 centile space. Red flags: weight loss, constipation or diarrhoea, headaches, vomiting, abnormal fat stores, disproportion, dysmorphic features, anaemia, delayed puberty, clinical features of hypothyroidism or other chronic illness. Tall stature or accelerated growth (height >98th centile, or an increase of 1 centile space over more than a year before puberty) also merits assessment. Referral is recommended for girls with no signs of puberty by 13 and boys by 14. Heights should be measured accurately and plotted on growth charts (September 2021). www.bsped.org.uk/media/oo1hsxet/clinical-standards-for-growth-assessment-and-referral-criteria-for-children-with-a-suspected-growth-disorder.pdf