Note: Wikipedia IGF-1 Insulin-like growth factor 1
Dr Cannell, in response your suggestion in your April 30 Vitamin D Newsletter, I have
had my IGF-1 measured, with a result of 83 ng/ml, reference level of 55-166. I should
have mentioned that I am a 91.5 year old male in reasonably good health. I have been
taking vitamin D since I read your article about vitamin D and influenza in an 2007
issue of LE Magazine. My present 25OH D level is 97 ng/ml, taking 12k iu/day. I am
increasing my D intake to 17k iu in an attempt to get my 25OH D up to around 110 ng/ml,
rechecking my IGF-1 and then letting you know the result.
I have noticed several physical features about my body that might be due to increased HGH (IGF-1) readings:
- I have far fewer facial wrinkles than others my age.
- A long term “frozen” right shoulder has returned to normal with no treatment.
- After having afib problem for l0 years, a third cardioversion procedure, when my
- 25 OH D was 97 ng/ml, was successful and my heart has been normal for the last ten months.
However, I believe that if vitamin D has the ability to stimulate IGF-1 production, then medicine might have a practical way to fight aging mental decline.
There are many studies showing a positive relationship between IGF-1 levels and aging mental abilities.
Jan B. Deijen, writing in a 2011 paper entitled The GH/IGF-1 Axis and Cognitive Changes Across a 4 Year Period in Healthy Adults, sums it up by writing
The results suggest that higher serum levels of GH and IGF-1 preserve the quality of working memory functions over the years
(PDF is attached at the bottom of this page)
Congratulations to you, Dr Cannell for reading the Kanellakis paper and noticing how 400 iu/day of vitamin D increased IGF-1 levels of the study participants by about 10%.
Regards, Millard Ferguson
Changes in Parameters of bone metabolism in postmenopausal women following a 12-month intervention period using dairy products enriched with calcium, vitamin D, and phylloquinone (vitamin K(1)or menaquinone-7 (vitamin K (2)): the Postmenopausal Health Study II.
Calcif Tissue Int. 2012 Apr;90(4):251-62. doi: 10.1007/s00223-012-9571-z. Epub 2012 Mar 4.
Kanellakis S, Moschonis G, Tenta R, Schaafsma A, van den Heuvel EG, Papaioannou N, Lyritis G, Manios Y.
Department of Nutrition and Dietetics, Harokopio University, Kallithea, Athens, Greece.
The objective of the present study was to examine the effect of dairy products enriched with calcium, vitamin D(3), and phylloquinone (vitamin K(1)) or menaquinone-7 (vitamin K(2)) on parameters of bone metabolism in postmenopausal women following a 12-month intervention. Postmenopausal women were divided into three intervention groups and a control group (CG). All three intervention groups attended biweekly sessions and received fortified dairy products providing daily 800 mg of calcium and 10 ?g of vitamin D(3) (CaD). Furthermore, in two of the three intervention groups the dairy products were also enriched with vitamin K, providing daily 100 ?g of either phylloquinone (CaDK1) or menaquinone-7 (CaDK2). The increase observed for serum 25(OH)D levels in all intervention groups and the increase observed for serum IGF-I levels in the CaDK2 group differed significantly compared to the changes observed in CG (P = 0.010 and P = 0.028, respectively). Furthermore, both the CaDK1 and CaDK2 groups had a significantly lower mean serum undercarboxylated osteocalcin to osteocalcin ratio and urine deoxypyridinoline levels at follow-up compared to the CaD and CG groups (P = 0.001 and P = 0.047, respectively). Significant increases in total-body BMD were observed in all intervention groups compared to CG (P < 0.05), while significant increases in lumbar spine BMD were observed only for CaDK1 and CaDK2 compared to CG (P < 0.05) after controlling for changes in serum 25(OH)D levels and dietary calcium intake. In conclusion, the present study revealed more favorable changes in bone metabolism and bone mass indices for the two vitamin K-supplemented groups, mainly reflected in the suppression of serum levels of bone remodeling indices and in the more positive changes in lumbar spine BMD for these two study groups.
- Random controlled trial where all groups got 800 mg of Calcium and 400 IU of vitamin D
- One group (CaDK1) also had 100 micrograms of Vitamin K1
- One group (CaDK2) also had 100 micrograms of Vitamin K2
- increased serum IGF-I, a hormone that promotes growth and proliferation.
- Both Vitamin K groups had
- Improved osteocalcin (which keep Calcium from being deposited in wrong locations)
- Increased backbone density
Search PubMed for "insulin-like growth factor" "vitamin d" 512 items as of Oct 2017
- Search IGF in VitaminDWiki 252 items as of Oct 2017
- Growth hormone increased height of children more if higher levels of vitamin D – Aug 2015
- Overview Vitamin K and Vitamin D
- Overview Cognition and vitamin D
- 5700 IU vitamin D improved various growth factors in overweight people – Oct 2012
- Human grown hormone (IGF1) in seniors greatly increased with 7,000 IU of vitamin D – Sept 2013
- PubMed search: (aging OR "cognitive decline" OR cognition) "vitamin d" "vitamin K" 46 items as of Oct 2017
Hormonal Therapy of Intrinsic Aging - 2012
Curr Pharm Biotechnol. 2006 Apr;7(2):125-32.
Endocrinology Service, Ciudad Sanitaria de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain. jmgs at csub.scs.es
Several factors are known to be involved in the regulation of vitamin D and sunlight and diet are the two sources in humans, but the relative importance of each of them is not well defined. Vitamin D, parathyroid hormone and serum insulin-like growth factor-I (IGF-I) were found to be independent predictors of total bone density. Thus, the growth hormone (GH)/IGF-I is thought to play an important role in the regulation of bone mineral density and the skeleton is second only to the liver as a source of circulating levels of IGF-I. The mechanisms by which IGF-I may influence bone metabolism is not fully understood but they are a predictor of bone mass density and are positively associated with vitamin D concentrations. There is a physiological decline of the GH/IGF axis with ageing. The high affinity IGF-binding proteins (IGFBP-I to 6) have also been involved in IGF-I regulation, and it is important to include the IGF-independent properties, particularly those of IGFBP3 that may be involved in the osteoblastic differentiation observed in human bone marrow stromal cell cultures. These hormones have been shown to up regulate each other.
1,25-(OH) D(3) has been shown to promote the action of IGF-I by increasing IGF-I receptors and IGF-I can also elevate 1,25-(OH) D(3) concentrations by stimulating the hydroxylation of 25-(OH) D(3) in the active 1,25-(OH) D(3) hormone.
Both GH and IGF-I significantly increased renal 1alpha-hydroxylase expression and serum 1, 25-(OH) D(3) concentrations.
In prostate cells, 1,25-(OH) D(3) is growth inhibitory for many established cell lines and the role of IGFBPs, especially IGFBP-3, can be growth inhibitory or stimulatory and IGFBP-3 expression increases in response to 1,25-(OH) D(3), or its analogs, in established prostate cancer cell lines.
Body fat is inversely associated with 25-(OH) D(3) in relation to with anthropometric measures, indicating a specific role of adipose tissue. IGF-I may be involved in both normal and abnormal fetal growth and stimulation of IGF-I synthesis during normal pregnancy may be associated with an increase in GH production by the placenta. Thus, maternal and umbilical cord serum IGF-I and 1,25-(OH) D(3) concentrations are lower in preeclampsia and umbilical cord serum IGF-I, IGFBP-1 and IGFBP-3 concentrations are associated with low newborn birth weights.