Paediatric doctors and doctors in general know very little about dentistry. They study the mouth and supporting structures for a couple of hours . A dentist studies for years and continues those studies all through their life.
Modern understanding of decay has been very much informed by the war years and rationing with the subsequent improvement in oral health associated with decreased sugar consumption. There was less chance of someone loosing teeth during rationing and the war.
Most adults will lose their teeth because of gum disease and indeed if you speak to the older generation it was "pyorrhoea " (old fashioned name for gum disease) that meant they had their teeth removed at a young age.
Stress, smoking , pregnancy hormones and nutrition can certainly have an effect on gum disease .
The "body" does not actively deposit calcium or phosphorus in teeth once they are formed. The only live part of a tooth is the pulp (nerve and blood vessels) which is inside the tooth (see previous reference) and research actively shows that even in people with gross calcium deficiencies no mineral is taken from the tooth by "the body".
Demineralisation and remineralisation of teeth can be demonstrated in vitro ie in a test tube with cow enamel. Put a tooth in acid it demineralises , put it in a suitably neutral solution with a remineralising solution and if the damage is not too great it will remineralise. Tooth decay prevention is all about keeping acid away from enamel. What you eat is essential in keeping the acid away.
There is very widespread evidence that dental decay , along with many other diet related diseases , actually improved during the war and into rationing period.
Indeed amongst populations that may have had very poor nutrition generally ie post war Japan , Tanzania etc tooth decay was virtually unknown until the introduction of a western, high sugar diet . In Iraq where nutrition of the general population has dropped following the war the decay rate has also dropped because a lot less sugar is eaten https://www.cambridge.org/core/journals/public-health-nutrition/article/new-understanding-of-the-relationship-between-sugars-dental-caries-and-fluoride-use-implications-for-limits-on-sugars-consumption/0FF6455AFB95AAE91DBD1636C3DE2C7C
I could say I am a dentist of many years standing , who has also taught other dentists but you have no proof of that.
It is an utter myth that pregnancy takes mineral from the mothers teeth. This is an extract about very old research
"There is a common belief that calcium from the mother’s teeth may be leached during pregnancy in a similar way to maternal bone in order to help the growth of the developing baby. However, studies have actually found this not to be the case. Way back in 1943, David Dragiff and Macwel Karshan undertookdetailed chemical analyses of teeth extracted from pregnant and non-pregnant women. They found little differences in the mineral content in the teeth of the pregnant women, and importantly, no reduction in the levels of calcium. The teeth of women do not ‘soften’ during pregnancy, and this theory is simply false."
The problem you will find is that the link between sugar intake and decay was proved over 70 years ago and the research to say calcium is not "taken" from pregnancy womens teeth is also over 70 years old. The research showing that decay in populations is not related to general nutrition levels but to ingestion of sugar is also 70 years old with many,many studies since. understanding of reversing very early decay has become more subtle but the universally taught truth in undergraduate and post graduate dentistry is , generally , cut down the sugar cut out the decay. No food or mineral supplementation has an effect other than adding fluoride but even this cannot overcome frequent sugar consumption.