Table 6.

 Evidence of relation between high vitamin D concentrations or vitamin D supplementation and clinical outcomes

Evidence category*	Health benefits	Heath risks
Convincing	None	None
Probable	Decreases risk of dental caries in children	None
	Increases levels of birth weight and maternal vitamin D concentrations at term
	Decreases levels of parathyroid hormone concentrations in CKD RD
Suggestive	Decreases risk of colorectal cancer, non-vertebral fractures, CVD, CVD prevalence, hypertension, ischaemic stroke, stroke, cognition, depression (cohort studies), body mass index, metabolic syndrome prevalence, type 2 diabetes, small for gestational age birth, gestational diabetes mellitus	Increases rate of falls (community) and risk of hypercalcaemia in CKD NRD
	Decreases levels of balance sway, alkaline phosphatase concentrations in CKD RD, parathyroid hormone concentrations in CKD NRD
	Increases levels of head circumference at birth, LDL, bone mineral density in femoral neck, muscle strength
No conclusion	Decreases risk of ankylosing spondylitis, Crohn’s disease, multiple sclerosis, osteoarthritis, rheumatoid arthritis, rheumatoid arthritis activity, scleroderma, systemic lupus erythematosus, thyroid autoimmunity, type 1 diabetes, type 1 diabetes in childhood (maternal vitamin D status), vitiligo, breast cancer, breast cancer prognosis, colon cancer, colorectal adenoma, colorectal adenoma recurrence, colorectal cancer prognosis, lung cancer, melanoma prognosis, non-Hodgkin’s lymphoma, non-small cell lung cancer prognosis, oesophageal cancer, ovarian cancer, prostate cancer prognosis, rectal cancer, renal cancer, stomach cancer, CVD in ethnic minorities, CVD mortality, hypertension in children, ischaemic heart disease, myocardial infarction, Alzheimer’s disease, depression (case-control studies), active tuberculosis, acute respiratory infection, infectious disease mortality, metabolic syndrome in ethnic minorities, obesity in ethnic minorities, type 2 diabetes in ethnic minorities, type 2 diabetes prevalence, allergic rhinitis and atopic dermatitis/eczema (maternal vitamin D status), cerebral function and diseases (maternal vitamin D status), childhood infections (maternal vitamin D status), wheezing and asthma in childhood (maternal vitamin D status), bacterial vaginosis in pregnant women, fertility, postpartum depression, pre-eclampsia in pregnant women, pregnancy associated breast cancer, bone health in pregnant and lactating women, bone pain in CKD RD, falls, rate of falls (care facilities), fractures in older people, fractures in CKD RD, hip fractures, non-vertebral non-hip fractures, vertebral fractures or deformity, performance measures in older people, rickets in children, all cause mortality, mortality in CKD, risk of requiring dialysis in CKD NRD, parathyroidectomy in CKD RD, subperiosteal erosions in CKD RD, mammographic breast density	Increases risk of pancreatic cancer, hyperphosphataemia in CKD, vascular calcification in CKD RD, hypercalcaemia in CKD RD
	Decreases levels of HDL in children, LDL in children, triglycerides in children, insulin/glucose metabolism in children, triglycerides, insulin resistance of diabetes patients, bone mineral density, bone mineral density in forearm, alkaline phosphatase concentrations in CKD NRD, creatinine clearance in CKD
	Increases levels of total cholesterol concentrations, neonatal and infant growth, length of gestation, bone mineral content in infants, bone mineral density in hip, bone mineral density in lumbar spine (children)
Substantial effect unlikely	Decreases risk of aggressive prostate cancer, premenopausal breast cancer, postmenopausal breast cancer, cancer mortality, kidney cancer, prostate cancer, caesarean section	None
	Decreases levels of fasting glucose in diabetes patients, HDL, adiposity in children (maternal vitamin D status)
	Increases levels of birth length (maternal vitamin D status), bone mineral density in children, bone mineral density in forearm in children, bone mineral density in hip in children, bone mineral density in lumbar spine, lower extremity strength

CKD=chronic kidney disease; CVD=cardiovascular disease; HDL=high density lipoprotein; LDL=low density lipoprotein; NRD=not requiring dialysis; RD=requiring dialysis.

*See box.