Does degree of baldness influence vitamin D status?
OBJECTIVE
To determine the association, if any, between male-pattern hair loss (baldness) and serum 25-hydroxyvitamin D (25-OHD) levels.


METHODS
A cross-sectional study of 296 healthy middle-aged and older men.


METHODS
Degree of baldness was independently assessed by two researchers using the Hamilton-Norwood scale and serum 25-OHD was measured in all men.


RESULTS
Classification of the degree of baldness by the two researchers showed a high level of agreement (kappa = 0.93). Forty-eight per cent of men had no hair loss or mild frontotemporal recession, 15% had predominant vertex loss, and 37% had significant scalp and vertex loss. After data were adjusted for potential confounding factors - including age, month of 25-OHD measurement, exercise levels, use of sunscreen, skin type and frequency of outdoor hat wearing - no significant differences in 25-OHD levels between these groups was detected (P = 0.60).


CONCLUSIONS
The degree of baldness does not appear to influence serum 25-OHD levels. The high prevalence of baldness in older men does not explain sex differences in 25-OHD levels. Other novel hypotheses are required to help determine whether baldness serves any physiological purpose.
Bolland
Mark J
MJ
Department of Medicine, University of Auckland, Auckland, New Zealand. m.bolland@auckland.ac.nz
Ames
Ruth W
RW
Grey
Andrew B
AB
Horne
Anne M
AM
Mason
Barbara H
BH
Gamble
Greg D
GD
Reid
Ian R
IR
D000328:Adult; D000505:Alopecia / Q000097:blood* / Q000145:classification; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C104450:25-hydroxyvitamin D