Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about Osteo-Malacia.

And you can find written notes on this topic at 0.com slash osteomalacia or in the

Rheumatology section of the second edition of the zero to finals medicine book,

which is available now on Amazon. So let's get straight into it.

Osteo-Malacia is a condition where defective bone mineralization causes soft bones. Oseo refers to bone and Malaysia means soft.

It's the result of insufficient vitamin D. The same process in children causes rickets.

Let's go through some simplified pathophysiology.

Vitamin D is a hormone the skin creates in response to sunlight.

It's also obtained in limited amounts from food.

It's vital in regulating bone mineralization, hormone secretion and immune function.

Low vitamin D is very common.

Vitamin D is created from cholesterol in the skin in response to UV radiation.

Patients with darker skin require more prolonged sun exposure to generate the same amount of

vitamin D. It's also obtained from food as a fat soluble vitamin. A regular diet does not

contain enough vitamin D to compensate for reduced sun exposure.

Patients with malabsorption disorders, for example inflammatory bowel disease, are at higher risk of vitamin D deficiency.

Patients with chronic kidney disease are also at higher risk as the kidneys help convert

vitamin D into its active form.

Vitamin D is essential in calcium and phosphate absorption in the intestines and reabsorption in the kidneys.

It's also responsible for regulating bone turnover and promoting bone reabsorption to increase the serum

calcium level. Inadequate vitamin D leads to a low serum calcium and a low serum phosphate.

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