Hubby had a vitamin D blood test done 2 weeks ago & results came back as 8! Nurse said she had never seen results this low before. I'm 28wks preg & so worried about him, he's not been well lately, he's had a cough for 6weeks now & doctors have said he has suspected TB. He's going for tests for this.
He's generally very weak lately, low energy levels, lost some weight, generally not himself 
What can this low vitamin defiency cause?