Loading...

Toggle Health Problems and D

High-level clouds decrease potential vitamin D by 40 percent – Oct 2012

Influence of high levels of cloud cover on vitamin D effective and erythemal solar UV irradiances.

Photochem Photobiol Sci. 2012 Oct 30.
Parisi AV, Turnbull DJ, Downs NJ.
University of Southern Queensland, Toowoomba, Queensland 4350, Australia. parisi at usq.edu.au.

The solar irradiances for the initiation of vitamin D synthesis (UV(D3)) have been measured concurrently with the amount of cloud cover to investigate the influence of high cloud cover fraction. The cases of 6.5 and more octa cloud cover were considered for five solar zenith angle (SZA) ranges up to 80°. For each of the SZA ranges, the UV(D3) reduced due to the high cloud cover. The average of the ratios of the UV(D3) irradiances on a cloudy day to those on a clear day with the corresponding ozone and SZA are

0.71 for the 6.5-7.5 octa cloud and
0.45 for the more than 7.5 octa cloud ranges.

The exposure times necessary to receive 1/3 MED to a horizontal plane were found to increase as the amount of cloud cover increased. For each cloud cover category, the range of values increased with cloud cover and with SZA. This research shows that the current public recommendations on the times of solar UV exposures required to produce adequate vitamin D are inappropriate for situations of more than 6.5 octa cloud.
PMID: 23108371

See also Vitamin D Life

UV in cloudy conditions – Sept 2010
CLICK HERE to search Vitamin D Life for "cloud cover" 99 items as of April 2014

High-level clouds decrease potential vitamin D by 40 percent – Oct 2012

2038 visitors, last modified 25 Apr, 2014,

Printer Friendly PDF this page! Follow this page for updates

This page is in the following categories (# of items in each category)

Noontime sun and D 302

Edit Comments

See any problem with this page? Report it (FINALLY WORKS)

“One pill every two weeks fights diabetes, cancers, heart failure, and 18 other diseases.”

Click for details

Health Problems and D

Acne (20+) studies)

Attention Deficit Hyperactivity Disorder (35+)

Allergy Overview

Amyotrophic Lateral Sclerosis (30+)

Alzheimer's Overview

Ankylosing Spondylitis (15+)

Antibiotics & Pro (84+) Overview

Arthritis see:

Asthma Overview

Atopic Dermatitis Overview (18+)

Autism (133+) Overview

Autoimmune (163+)

Back Pain (37+)

Bipolar Disorder (14+)

Bone - Health (269+)

Breathing (380+)

Burns, wounds (30+)

Cancer (209+) Overview

After diagnosis (84+)
Bladder (24+)
Breast (222+) Overview
Colon (114+) Overview
Leukemia (16+)
Liver (13+)
Lung (49+) Overview
Lymphoma(22+)
Other (55+)
Ovarian (21+)
Pancreatic (54+)
Prostate (91+) Overview
Skin (110+) Overview

Cardiovascular (425+) Overview

Carpal Tunnel Syndrome (12+)

Cerebral Palsy (6+)

Cholesterol (47+) Overview Cholesterol and vitamin D)

Chronic Fatigue Overview

Cognitive (290+) Overview

Colds and flu Overview

Concussions (25+)

Chronic obstructive pulmonary disease (17+)

COVID-19 (150+)

Cystic Fibrosis (41+)

Dental (77+)

Depression (214+)

Diabetes (451+) Overview

Diseases gen.+ misc, (93+)

Ear (11+)

Endometriosis (8+)

Falls/Fractures (215+) Overview

Fatigue, Chronic Overview

Fertility and sperm (109+)

Fibromyalgia Overview

Fractures Overview

Genetics (266+)

Gestational Diabetes (34+)

Gout (13+)

Gut (167+) Overview

Hair (20+)

Health - general (92+)

Hepatitis-B (9+)

Hepatitis-C (13+)

Human Immunodeficiency Virus (38+) Overview

Hives (10+)

Hypertension (133+) Overview

Hyperparathyroid Overview

Immunity (187+)

Infant-Child (605+)

Inflammation (135+)

Infection (16+)

Influenza Overview

Kidney (193+) Overview

Kidney Stones (23+) Overview

Leprosy (16+)

Liver (88+) Overview

Lupus (60+)

Myalgic Enceph. Overview

Mental Illness (20+)

Mental Stress (5+)

Metabolic Syndrome (84+) Overview

Migraine Headache (4+)

Military (27+)

Mortality (200+)

Multiple Sclerosis (355+) Overview

Muscle (18+)

Myopia (17+)

Obesity (346+) Overview

Osteoarthritis (49+) Overview

Osteoporosis (189+) Overview

Pain - chronic (137+) Overview

Parkinson (81+) Overview

Photosensitivity (3+)

Pneumonia (15+)

Pollution (31+)

Pregnancy (750+) Overview

Psoriasis (55+)

Respiratory Tract Infection (8+)

Restless Legs Syndrome (15+)

Rheum. Arth (101+) Overview

Rickets (119+) Overview

Sarcopenia (28+)

Schizophrenia Overview

Seniors (340+) Overview

Sepsis (16+)

Shin splints (4+)

Sickle Cell (17+) Overview

Skin (97+) Overview

Dark (419+) Overview

Sleep (70+)

Smoking (33+)

Spinal Cord (18+)

Spinal Surgery (13+)

Sports (230+) Overview

Statins (40+)

Stroke (95+) Overview

Thyroid/Parath. (70+) Overview

Trauma and surgery (277+)

Tuberculosis (107+) Overview

Urinary Tract Infection (15+)

Virus (343+)

Vision (76+)

Women (139+) Overview

Youth (148+)

# of studies as of Oct 6, 2020