I happened across a paper earlier which expressly mentioned using thyroxine, Flurazepam and B12 to help restore sleep patterns. Interesting indeed.
It does not appear to have been cited by many other papers - but it is mentioned in a review paper from 2010 - link lower down.
Successful treatment of human non-24-hour sleep-wake syndrome.
Kamgar-Parsi B, Wehr TA, Gillin JC.
The authors report a case in which a non-24-h (hypernychthemeral) sleep-wake cycle appeared as a late complication of a more fundamental disturbance in the quality of sleep (difficulty falling asleep, frequent awakenings, nonrefreshing sleep). The sleep disturbance began abruptly after a series of stressful events. The patient reported that he extended his hours of bedrest in the morning in order to increase his total sleep time and feel mor rested, and that he gradually extended his hours of activity in the late evening in order to increase his drowsiness and ability to fall asleep. At first this behavior, which was a deliberate attempt to compensate for inefficient nighttime sleep, led to a delayed sleep period, as also occurs in the delayed sleep phase syndrome. After several years in which sleep efficiency progressively deteriorated, this behavior led to a non-24-h free-running sleep-wake cycle. After the patient was treated with thyroxine for borderline hypothyroidism, and then flurazepam and finally vitamin B12, his sleep disturbance progressively improved and his sleep-wake cycle shortened. After B12 treatment he was able to advance the timing of his sleep period for the first time in nearly 10 years and to follow a normal 24-h sleep-wake regimen.
PMID: 6622881 [PubMed - indexed for MEDLINE]
Use of B12 for sleep seems to be relegated to a lesser place in this recent freely-accessible review on sleep:
And the thyroxine mentioned in the first article is simply not mentioned at all.
I wonder if B12 only helps in some cases - most obviously, if B12 is actually low!
Blog title from:
Shakespeare Henry IV Act 3 Scene 1
Picture is a slide of the impact of insomnia.