Most author names are capitalised. However, some names begin with lowercase prefixes like de, d’, van or von, and many social media usernames begin with a lowercase letter or are entirely in lowercase. In such cases, include the name in both the citation and the reference list in the same way the author has presented it in their work, unless the name begins a sentence.
…as found by von Martels, van de Meeberg, Holman, Ligtenberg, and ter Maaten (2013).
seen on a library Instagram feed (uoplibrary, 2016).
but at the start of a sentence:
Von Martels, van de Meeberg, Holman, Ligtenberg, and ter Maaten (2013) found…
Uoplibrary (2016) shows that some libraries have active accounts on Instagram.
Reference list entries
Keep the author’s original capitalisation in the reference list entries, including at the start of the reference, for example:
von Martels, J. Z. H., van de Meeberg, E. K, Holman, M., Ligtenberg, J. J. M., & ter Maaten, J. C. (2013). Pseudolithiassis after recent use of ceftriaxone: An unexpected diagnosis in a child with abdominal pain. American Journal of Emergency Medicine, 31(8), 1294-1296.