In order to help my child grow taller, I make sure they take calcium and Vitamin AD every day, but I’ve also heard that too much can advance bone age and actually prevent them from growing tall!
In the outpatient clinic, we occasionally receive consultations like this. Parents on one hand treat calcium and Vitamin AD as if they were “miracle growth cures,” yet they worry that they might become “height killers.”
So, today we are going to have an objective discussion about how to consume calcium and vitamins properly, and what the actual risk factors are for advanced bone age.
Do excessive intakes of calcium and Vitamin AD lead to advanced bone age?
The answer is no. Currently, there is no research proving that normal intake of calcium or Vitamin AD directly leads to advanced bone age, nor does it cause a sudden increase in height.
While some health supplements can cause advanced bone age, they are primarily sex hormone-based and do not include calcium and Vitamin AD.
So, does this mean that we can freely supplement Vitamin D or calcium? Of course not. The body needs these nutrients, and it’s fine to consume them in moderation, but excessive intake also carries other risks.
1. Calcium supplementation
Calcium is an important component of the human body, with 99% of it existing in bones and teeth. It is not only a builder of the skeletal framework but also participates in various physiological activities at the core of life, from muscle contraction to blood coagulation, cardiovascular function regulation, activation of various enzyme activities, gene regulation, and other processes, all of which are indispensable.
However, under normal circumstances, children without underlying diseases, who consume an adequate amount of milk and regularly supplement with Vitamin D, do not need additional calcium supplements.
For further reading👇:
1. Calcium supplementation without a word! Are you really supplementing correctly?
2. Those who should supplement do not, those who should not, supplement instead—this is about calcium
Excessive calcium supplementation not only fails to improve health but can also trigger a range of systemic diseases. Long-term excessive calcium can competitively inhibit iron absorption, leading to iron-deficiency anemia. It can also cause urinary system stones, cardiovascular calcification, gastric ulcers, paradoxical increase in bone fragility, fractures, and other hazards.
The daily recommended intake of calcium is as follows:
（Source: Calcium – Health Professional Fact Sheet）
Recommended milk intake, including equivalent calcium dairy products:
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0-3 months: Gradually increasing after starting milk, about 150ml/kg per day
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3-6 months: About 120ml/kg per day, 800-1000ml/day
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6-12 months: About 600-800ml/day
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1-3 years: About 400-500ml/day
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4-5 years: About 350-500ml/day
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School age: About 300ml/day
Appendix: Uptodate recommends different daily milk intakes for different age groups: 1-2 years: 2 cups of milk (about 480ml); 2-8 years: 2-3 cups of milk (about 480-720ml); 9-18 years: 3 cups (about 720ml).
Because dietary habits vary from country to country, and the calcium content from other foods varies, the recommended standards for milk intake differ from country to country.Considering the Chinese diet, which includes other high-calcium foods such as soy products, a milk intake of 400-500ml/day is usually arranged after the age of 1.
2. Vitamin A
Vitamin A is essential for maintaining the integrity of all epithelial tissues, with the most significant impact on the epithelia of the eyes, respiratory tract, digestive tract, urinary tract, and reproductive system. It can prevent diseases such as dry eye syndrome and night blindness, participate in light transduction and color vision formation, and plays a crucial role in cellular differentiation and integrity of the eyes.
Many foods are rich in Vitamin A. Animal-based foods include milk, eggs, liver, and others, which are rich in active Vitamin A. Plant-based foods include orange-yellow vegetables, green leafy vegetables, tomatoes, fruits, and others, which are rich in provitamin A( convertible into Vitamin A in the body).
If your diet includes some orange-yellow or green vegetables, the intake of Vitamin A is likely to meet the body’s needs.
For further reading👉：Is China’s children lacking Vitamin A? Do children need extra supplements?
Vitamin A (unit conversion: 1ug=3.3IU, source: Uptodate)
Excessive supplementation of Vitamin A can lead to Vitamin A toxicity, with acute toxicity in infants and young children presenting symptoms such as bulging fontanelles, increased tension, accompanied by nausea, vomiting, and neurological symptoms such as fatigue, drowsiness, or overexcitement. In older children, headaches may occur, occasionally with blurred vision, double vision, and severe cases may exhibit pseudotumor cerebri symptoms.
Subacute or chronic toxicity manifestations are diverse and not easily noticed in the early stages, mainly affecting the skin, mucous membranes, and neuromuscular system. Symptoms include blurred vision, headache(may be the initial symptom), loss of appetite, irritability, low-grade fever, digestive disorders, hair thinning, dryness, falling out, skin dryness, maculopapular rash, itching, peeling, and hyperpigmentation, cracked and bleeding corners of the mouth, pain and swelling at the muscle attachment points of the limbs with osteoporosis, anemia, limb pain, hepatosplenomegaly, etc.
3. Vitamin D
Vitamin D and its metabolites play important clinical roles, being related to calcium homeostasis and bone metabolism.Vitamin D is rarely naturally found in foods(except for fatty fish).
When the human skin is exposed to ultraviolet rays in sunlight, 7-dehydrocholesterol present in the skin is converted into a precursor of Vitamin D3, and after temperature-dependent rearrangement, Vitamin D3 is formed.
However, ultraviolet irradiation of the skin, while bringing Vitamin D, also increases the risk of skin cancer. After weighing the pros and cons, it is recommended that people take active sun protection when outdoors.
As a result, the synthesis rate of Vitamin D in the skin is almost zero, so it is recommended to actively take oral Vitamin D supplements to ensure a sufficient source of Vitamin D.
Vitamin D (unit: ug, unit conversion: 1ug=40IU, source: Uptodate)
Similarly, excessive supplementation of Vitamin D can also be harmful. Symptoms of acute Vitamin D toxicity are caused by hypercalcemia, including confusion, polyuria, thirst, anorexia, vomiting, and muscle weakness. Chronic toxicity may cause nephrocalcinosis, bone demineralization, and pain.
Similarly, excessive supplementation of Vitamin D can also be harmful. Because the individual differences in the toxic dose of Vitamin D are large, it is currently unclear how much Vitamin D intake will definitely lead to poisoning. It is generally believed that children taking 500-1250μg（20000～50000IU）or 50μg/kg（2000IU/kg）daily for several weeks or months can develop poisoning, but sensitive individuals taking only 100μg（4000IU）daily for 1 to 3 months can become poisoned.
Anda single intake of more than 50000IU may cause acute poisoning. Symptoms of acute Vitamin D toxicity are caused by hypercalcemia, including confusion, polyuria, thirst, anorexia, vomiting, and muscle weakness. Chronic toxicity may cause nephrocalcinosis, bone demineralization, and pain.
What causes advanced bone age?
Bone age reflects the maturity of the skeleton and can assess an individual’s growth potential and the trend of sexual development maturity. Combining bone age can predict a child’s adult height through certain methods.
Bone age is influenced by various factors including gender, race, nutrition, health, environment, genetics, and developmental status. Although there are rules to follow, the range and variation are very large, and it is common for bone age to not completely match the actual age. For situations where bone age needs to be measured, you can refer to this popular science article👇:
Is bone age testing a智商 tax? Pediatrician: No, these situations require measurement
The common causes of advanced bone age include the following:
1. Pathological disease factors
Precocious puberty (the most common cause): This is the main reason for the advancement of bone age.
Endocrine system abnormalities: Congenital adrenal hyperplasia, hyperthyroidism, etc.
Genetic syndromes: McCune-Albright syndrome (Polyostotic fibrous dysplasia with endocrine abnormalities).
Neoplastic lesions: Intracranial space-occupying lesions
(such as hamartomas)
or other metastatic malignancies.
For further reading👉：Parents must understand the secrets of their children’s adolescent development
2. Environmental and lifestyle factors
Endocrine disruptors (EDCs): Plastic products, such as Bisphenol A (BPA), Phthalates (plasticizers), etc.; Pesticide residues, such as DDT metabolites (DDE), etc.; Industrial pollutants, such as Polychlorinated Biphenyls (PCBs), heavy metals (lead, cadmium), etc. These environmental endocrine disruptors may interfere with the endocrine axis through estrogen receptor mediation, inhibition of hormone metabolism enzymes, and other pathways, causing precocious puberty and advanced bone age.
Nutritional metabolic imbalance: Obesity caused by high-calorie diets. When obese, the activity of aromatase in body fat tissue increases, leading to an increase in the conversion of androgens to estrogens, which in turn leads to advanced bone age and accelerated epiphyseal closure.
3. Iatrogenic and exogenous factors
Medication exposure risks: Hormonal preparations, such as creams and washes containing estrogen/androgen; misuse of health supplements, such as unmarked “height-increasing products” “strengthening agents” (often containing sex hormone-like substances).
Food contamination: Meat with hormone residues from the misuse of unregulated growth promoters, plant estrogens (excessive intake of soy isoflavones, etc.).
Finally, remember: too much is as bad as too little, extremes are contrary to the balance. The human body is like a delicate balance, and ‘moderation’ is the key to maintaining it. Calcium and Vitamin AD are important nutrients needed by the body, consume them appropriately, and do not over-supplement.
Advanced bone age is mostly caused by precocious puberty, obesity, endocrine diseases, or environmental pollutants (such as Bisphenol A, hormones in some health supplements), normal intake of calcium and Vitamin AD will not lead to advanced bone age.
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