It is just so agonizingly slow. But finally, one expert, based on a study of middle-class women, discovered what obstetricians who have been checking vitamin D levels all along have known for years: all pregnant women should have a vitamin D blood test. As this story shows, pregnant women are very likely to be vitamin D deficient.
While this story fails to discuss it, and I am unaware of any scientific papers on the subject, there may have been a big difference in calcium intake between Victorian times and modern times. Most people don’t think of rickets as a disease of calcium deficiency, but that’s what it is. Without enough vitamin D, not enough calcium gets absorbed and infants’ bones become weak.
However, one can get rickets with normal vitamin D levels, as equatorial African researchers have repeatedly documented, if calcium intake is low enough.
In fact, a good question is: what works better to cure rickets, vitamin D or calcium? In Nigeria, the answer is calcium, not vitamin D. Thank a South African scientist named John Pettifor for this important discovery.
So what was calcium intake in Victorian England? It is not entirely an academic question. I suspect calcium intake is much higher now than in Victorian times. One could predict that vitamin D deficiency, in the face of adequate calcium intake, would present differently in modern times, perhaps as asthma, autism, or autoimmune disorders (the three modern childhood epidemics) and not as often as rickets (the Victorian epidemic). In fact, with adequate dietary calcium, the first clinical presentation of modern childhood vitamin D deficiency may have nothing to do with bones.