Perhaps not take vitamin D in the evening

Can Vitamin D Replace Sunlight? A Stunning Discovery Seth's Blog Nov 2011

Taking 10,000 IU vitamin D at 7PM seemed to upset her awake/sleep cycle.
She thought is was like getting sunshine late a night
Sleep issues resolved by taking the vitamin D in mid-day
Single person

Updates on Seth's blog May, June 2012

Mid Morning seems much better than early morning or evening

Bulletproof Your Sleep with Vitamin D Bulletproof

Vitamin D is inversely related to melatonin, your sleep hormone, so it makes sense that taking it at night disrupts sleep. I’ve noticed this effect personally. For this reason, there is no reason to take vitamin D at night.
An n=1 experiment done by gwern.net also concludes that taking vitamin D in the morning is best. Using a ZEO, his morning dose of D increased REM, deep sleep, and number of hours increased. He looked at taking the same dosage at night, and his sleep quality plummeted. (11)

7 Ways You Might Be Inadvertently Sabotaging a Good Night’s Sleep Mark's Daily Apple 2012

You’re taking vitamin D too late in the day.
When you think about light and food and activity as entrainers of our circadian rhythms, that the timing of our supplementation with vitamin D might affect our sleep makes intuitive sense. Because what is vitamin D but an indication of daylight, of bright morning or afternoon sun emanating UV rays? If getting sunlight “tells” our body that it’s daytime, perhaps taking vitamin D sends a similar message. Although there’s no clinical trial showing this effect, Seth Roberts has been receiving accounts from readers who modified the quality and duration of their sleep by changing when they took vitamin D. Tara Grant, one of our biggest success stories and the first person to notify Seth, chronicled her experiences on her blog:

I looked aghast at the 10,000 units of Vitamin D I was taking. It was 7 o’clock at night! I was essentially giving my body 15 minutes worth of bright sunlight energy. No wonder I was waking up in the middle of the night! I was telling my body that it wasn’t really time for bed, it was still the middle of the day.
I’m not surprised, and I wouldn’t be surprised if this worked for the diligent, dutiful Primal eater who’s been doing everything right but who gets bad sleep. And hey, say you try it and it doesn’t work, it doesn’t have any effect whatsoever on your sleep? No harm done.

The Important Links Between Vitamin D And Insomnia

“Vitamin D is known as the “sunshine vitamin” for a reason—sun exposure spurs the body to produce it. This also means that it’s an indicator of light and daytime. So when you take vitamin D, it decreases levels of melatonin, the hormone that helps control your sleep and wake cycles by naturally rising in the mid- to late-evening. In some experimental trials, taking vitamin D at night decreased REM sleep and the number of hours in nighttime slumber."

Note from Admin of Vitamin D Wiki

I have ceased using the UV lamp at night - stayed awake too long after using it.
Now just use it in the middle of the day

by the way - there are many books on chronobiology